diff --git a/README.md b/README.md
index 71366dd..2cbf484 100644
--- a/README.md
+++ b/README.md
@@ -132,7 +132,7 @@ public class Demo {
     ////////////////////////////////////////
 
     System.out.println("Is executor lazy? " +
-        containsInstanceOnWrapperChain(executor, LazyExecutorWrapper.class));
+        containsInstanceTypeOnWrapperChain(executor, LazyExecutorWrapper.class));
     // print true
 
     String busy = getAttachmentFromWrapperChain(executor, "busy");
@@ -208,7 +208,7 @@ public class IntegrationDemo {
     ////////////////////////////////////////
 
     System.out.println("Is executor ExistedExecutorWrapper? " +
-        containsInstanceOnWrapperChain(executor, ExistedExecutorWrapper.class));
+        containsInstanceTypeOnWrapperChain(executor, ExistedExecutorWrapper.class));
     // print true
     String adaptAttachment = getAttachmentFromWrapperChain(executor, "adapted-existed-executor-wrapper-msg");
     System.out.println("Adapted existed executor wrapper msg: " + adaptAttachment);
@@ -305,7 +305,7 @@ public class IntegrationDemoUsingWrapperAdapterUtils {
     ////////////////////////////////////////
 
     System.out.println("Is executor ExistedExecutorWrapper? " +
-        containsInstanceOnWrapperChain(executor, ExistedExecutorWrapper.class));
+        containsInstanceTypeOnWrapperChain(executor, ExistedExecutorWrapper.class));
     // print true
     String adaptAttachment = getAttachmentFromWrapperChain(executor, "adapted-existed-executor-wrapper-msg");
     System.out.println("Adapted existed executor wrapper msg: " + adaptAttachment);
diff --git a/src/main/java/io/foldright/inspectablewrappers/Inspector.java b/src/main/java/io/foldright/inspectablewrappers/Inspector.java
index d15846e..750df61 100644
--- a/src/main/java/io/foldright/inspectablewrappers/Inspector.java
+++ b/src/main/java/io/foldright/inspectablewrappers/Inspector.java
@@ -3,9 +3,13 @@
 import edu.umd.cs.findbugs.annotations.DefaultAnnotationForParameters;
 import edu.umd.cs.findbugs.annotations.NonNull;
 import edu.umd.cs.findbugs.annotations.Nullable;
+import org.jetbrains.annotations.Contract;
 
+import java.util.ArrayList;
 import java.util.IdentityHashMap;
+import java.util.List;
 import java.util.Optional;
+import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.function.Supplier;
@@ -19,7 +23,7 @@
  * <h2>Common simple usages</h2>
  * <ul>
  * <li>Reports whether any instance on the wrapper chain matches the given type
- *     by static method {@link #containsInstanceOnWrapperChain(Object, Class)}
+ *     by static method {@link #containsInstanceTypeOnWrapperChain(Object, Class)}
  * <li>Retrieves the attachment of instance on the wrapper chain
  *     by static method {@link #getAttachmentFromWrapperChain(Object, Object)}
  * <li>Verifies the compliance of wrapper chain with the specification contracts
@@ -68,10 +72,9 @@ public final class Inspector {
      *                               or the adaptee of {@link WrapperAdapter} is null
      * @throws IllegalStateException if the adaptee of {@link WrapperAdapter} is an instance of {@link Wrapper}
      *                               or CYCLIC wrapper chain
-     * @see Wrapper#unwrap()
-     * @see WrapperAdapter#adaptee()
      */
-    public static <W> boolean containsInstanceOnWrapperChain(final W wrapper, final Class<?> instanceType) {
+    @Contract(pure = true)
+    public static <W> boolean containsInstanceTypeOnWrapperChain(final W wrapper, final Class<?> instanceType) {
         requireNonNull(wrapper, "wrapper is null");
         requireNonNull(instanceType, "instanceType is null");
         return testWrapperChain(wrapper, w -> isInstanceOf(w, instanceType));
@@ -104,10 +107,9 @@ private static boolean isInstanceOf(final Object o, final Class<?> clazz) {
      * @throws IllegalStateException if the adaptee of {@link WrapperAdapter} is an instance of {@link Wrapper}
      *                               or CYCLIC wrapper chain
      * @see Attachable#getAttachment(Object)
-     * @see Wrapper#unwrap()
-     * @see WrapperAdapter#adaptee()
      */
     @Nullable
+    @Contract(pure = true)
     @SuppressWarnings("unchecked")
     public static <W, K, V> V getAttachmentFromWrapperChain(final W wrapper, final K key) {
         requireNonNull(wrapper, "wrapper is null");
@@ -122,9 +124,88 @@ public static <W, K, V> V getAttachmentFromWrapperChain(final W wrapper, final K
         }).orElse(null);
     }
 
+    /**
+     * Gets the wrapper chain, aka. the list of all instances on the wrapper chain.
+     * <p>
+     * The wrapper chain consists of wrapper itself, followed by the wrappers
+     * obtained by repeatedly calling {@link Wrapper#unwrap()}.
+     *
+     * @param wrapper wrapper instance
+     * @param <W>     the type of instances that be wrapped
+     * @throws NullPointerException  if wrapped argument is null,
+     *                               or any wrapper {@link Wrapper#unwrap()} returns null,
+     *                               or the adaptee of {@link WrapperAdapter} is null
+     * @throws IllegalStateException if the adaptee of {@link WrapperAdapter} is an instance of {@link Wrapper}
+     *                               or CYCLIC wrapper chain
+     */
+    @NonNull
+    @Contract(pure = true)
+    public static <W> List<W> getInstancesOfWrapperChain(final W wrapper) {
+        List<W> ret = new ArrayList<>();
+        forEachOnWrapperChain(wrapper, ret::add);
+        return ret;
+    }
+
+    /**
+     * Gets the base of the wrapper chain, aka. the last instance of the wrapper chain.
+     * <p>
+     * The wrapper chain consists of wrapper itself, followed by the wrappers
+     * obtained by repeatedly calling {@link Wrapper#unwrap()}.
+     *
+     * @param wrapper wrapper instance
+     * @param <W>     the type of instances that be wrapped
+     * @throws NullPointerException  if wrapped argument is null,
+     *                               or any wrapper {@link Wrapper#unwrap()} returns null,
+     *                               or the adaptee of {@link WrapperAdapter} is null
+     * @throws IllegalStateException if the adaptee of {@link WrapperAdapter} is an instance of {@link Wrapper}
+     *                               or CYCLIC wrapper chain
+     */
+    @NonNull
+    @Contract(pure = true)
+    @SuppressWarnings("unchecked")
+    public static <W> W getBaseOfWrapperChain(final W wrapper) {
+        Object[] holder = new Object[1];
+        forEachOnWrapperChain(wrapper, w -> holder[0] = w);
+        return (W) holder[0];
+    }
+
+    /**
+     * Unwraps {@link Wrapper} to the underlying instance, a convenient method for {@link Wrapper#unwrap()}.
+     * <p>
+     * This method is {@code null}-safe, return {@code null} iff input parameter is {@code null};
+     * If input parameter is not a {@link Wrapper} just return input.
+     *
+     * @param obj wrapper instance
+     * @param <W> the type of instances that be wrapped
+     * @throws NullPointerException if {@link Wrapper#unwrap()} returns null
+     * @see Wrapper#unwrap()
+     * @see #isWrapper(Object)
+     */
+    @Nullable
+    @Contract(value = "null -> null; !null -> !null", pure = true)
+    @SuppressWarnings("unchecked")
+    public static <W> W unwrap(@Nullable final W obj) {
+        if (!isWrapper(obj)) return obj;
+        return (W) unwrapNonNull(obj);
+    }
+
+    /**
+     * Checks the input object is an instance of {@link Wrapper} or not,
+     * return {@code false} if input {@code null}.
+     *
+     * @see #unwrap(Object)
+     */
+    @Contract(value = "null -> false", pure = true)
+    public static boolean isWrapper(@Nullable Object obj) {
+        return obj instanceof Wrapper;
+    }
+
     /**
      * Verifies the compliance of wrapper chain with the specification contracts.
      * <p>
+     * The wrapper chain consists of wrapper itself, followed by the wrappers
+     * obtained by repeatedly calling {@link Wrapper#unwrap()}.
+     * <p>
      * more about the specification contracts see the doc of below methods:
      * <ul>
      * <li>{@link Wrapper#unwrap()}
@@ -138,15 +219,46 @@ public static <W, K, V> V getAttachmentFromWrapperChain(final W wrapper, final K
      *                               or the adaptee of {@link WrapperAdapter} is null
      * @throws IllegalStateException if the adaptee of {@link WrapperAdapter} is an instance of {@link Wrapper}
      *                               or CYCLIC wrapper chain
-     * @see Wrapper#unwrap()
-     * @see WrapperAdapter#adaptee()
      */
     public static <W> void verifyWrapperChainContracts(final W wrapper) {
         travelWrapperChain(wrapper, w -> Optional.empty());
     }
 
+    /**
+     * Verifies the compliance of wrapper chain with the specification contracts,
+     * and checks all instances on wrapper chain is an instance of the given {@code bizInterface}.
+     * <p>
+     * The wrapper chain consists of wrapper itself, followed by the wrappers
+     * obtained by repeatedly calling {@link Wrapper#unwrap()}.
+     * <p>
+     * more about the specification contracts see the doc of below methods:
+     * <ul>
+     * <li>{@link Wrapper#unwrap()}
+     * <li>{@link WrapperAdapter#adaptee()}
+     * </ul>
+     *
+     * @param wrapper wrapper instance
+     * @param <W>     the type of instances that be wrapped
+     * @throws NullPointerException  if wrapped argument is null,
+     *                               or any wrapper {@link Wrapper#unwrap()} returns null,
+     *                               or the adaptee of {@link WrapperAdapter} is null
+     * @throws IllegalStateException if any instance on the wrapper chain is not an instance of {@code bizInterface},
+     *                               or the adaptee of {@link WrapperAdapter} is an instance of {@link Wrapper}
+     *                               or CYCLIC wrapper chain
+     */
+    public static <W> void verifyWrapperChainContracts(final W wrapper, Class<W> bizInterface) {
+        travelWrapperChain(wrapper, w -> {
+            if (!bizInterface.isAssignableFrom(w.getClass())) {
+                throw new IllegalStateException("The instance(" + w.getClass().getName() +
+                        ") on wrapper chain is not an instance of " + bizInterface.getName());
+            }
+            return Optional.empty();
+        });
+    }
+
     /**
      * Reports whether any instance on the wrapper chain satisfies the given {@code predicate}.
+     * Exceptions thrown by the {@code predicate} are relayed to the caller.
      * <p>
      * The wrapper chain consists of wrapper itself, followed by the wrappers
      * obtained by repeatedly calling {@link Wrapper#unwrap()}.
@@ -161,8 +273,6 @@ public static <W> void verifyWrapperChainContracts(final W wrapper) {
      *                               or the adaptee of {@link WrapperAdapter} is null
      * @throws IllegalStateException if the adaptee of {@link WrapperAdapter} is an instance of {@link Wrapper}
      *                               or CYCLIC wrapper chain
-     * @see Wrapper#unwrap()
-     * @see WrapperAdapter#adaptee()
      */
     public static <W> boolean testWrapperChain(final W wrapper, final Predicate<? super W> predicate) {
         requireNonNull(wrapper, "wrapper is null");
@@ -173,10 +283,38 @@ public static <W> boolean testWrapperChain(final W wrapper, final Predicate<? su
         }).orElse(false);
     }
 
+    /**
+     * Performs the given action for each instance on the wrapper chain
+     * until all elements have been processed or the action throws an exception.
+     * Exceptions thrown by the {@code action} are relayed to the caller.
+     * <p>
+     * The wrapper chain consists of wrapper itself, followed by the wrappers
+     * obtained by repeatedly calling {@link Wrapper#unwrap()}.
+     *
+     * @param wrapper wrapper instance/wrapper chain
+     * @param action  The action to be performed for each instance
+     * @param <W>     the type of instances that be wrapped
+     * @throws NullPointerException  if any arguments is null,
+     *                               or any wrapper {@link Wrapper#unwrap()} returns null,
+     *                               or the adaptee of {@link WrapperAdapter} is null
+     * @throws IllegalStateException if the adaptee of {@link WrapperAdapter} is an instance of {@link Wrapper}
+     *                               or CYCLIC wrapper chain
+     * @see #travelWrapperChain(Object, Function)
+     */
+    public static <W> void forEachOnWrapperChain(final W wrapper, final Consumer<? super W> action) {
+        requireNonNull(wrapper, "wrapper is null");
+        requireNonNull(action, "action is null");
+        travelWrapperChain(wrapper, w -> {
+            action.accept(w);
+            return Optional.empty();
+        });
+    }
+
     /**
      * Traverses the wrapper chain and applies the given {@code process} function to
      * each instance on the wrapper chain, returns the first non-empty({@link Optional#empty()}) result
      * of the process function, otherwise returns {@link Optional#empty()}.
+     * Exceptions thrown by the process function are relayed to the caller.
      * <p>
      * The wrapper chain consists of wrapper itself, followed by the wrappers
      * obtained by repeatedly calling {@link Wrapper#unwrap()}.
@@ -192,12 +330,12 @@ public static <W> boolean testWrapperChain(final W wrapper, final Predicate<? su
      *                               or the adaptee of {@link WrapperAdapter} is null
      * @throws IllegalStateException if the adaptee of {@link WrapperAdapter} is an instance of {@link Wrapper}
      *                               or CYCLIC wrapper chain
-     * @see Wrapper#unwrap()
-     * @see WrapperAdapter#adaptee()
+     * @see #forEachOnWrapperChain(Object, Consumer)
      */
     @NonNull
     @SuppressWarnings("unchecked")
-    public static <W, T> Optional<T> travelWrapperChain(final W wrapper, final Function<? super W, Optional<T>> process) {
+    public static <W, T> Optional<T> travelWrapperChain(
+            final W wrapper, final Function<? super W, Optional<T>> process) {
         requireNonNull(wrapper, "wrapper is null");
         requireNonNull(process, "process is null");
 
@@ -216,7 +354,7 @@ public static <W, T> Optional<T> travelWrapperChain(final W wrapper, final Funct
                 if (r.isPresent()) return r;
             }
 
-            if (!(w instanceof Wrapper)) return Optional.empty();
+            if (!isWrapper(w)) return Optional.empty();
             w = unwrapNonNull(w);
             if (history.containsKey(w)) {
                 throw new IllegalStateException("CYCLIC wrapper chain" +
@@ -228,13 +366,14 @@ public static <W, T> Optional<T> travelWrapperChain(final W wrapper, final Funct
     /**
      * Gets adaptee of the given WrapperAdapter instance with {@code null} check and non-{@link Wrapper} type check.
      */
+    @Contract(pure = true)
     private static Object adapteeNonWrapper(final Object wrapper) {
         final Object adaptee = ((WrapperAdapter<?>) wrapper).adaptee();
 
         Supplier<String> msg = () -> "adaptee of WrapperAdapter(" + wrapper.getClass().getName() + ") is null";
         requireNonNull(adaptee, msg);
 
-        if (adaptee instanceof Wrapper) {
+        if (isWrapper(adaptee)) {
             throw new IllegalStateException("adaptee(" + adaptee.getClass().getName() +
                     ") of WrapperAdapter(" + wrapper.getClass().getName() +
                     ") is an instance of Wrapper, adapting a Wrapper to a Wrapper is UNNECESSARY");
@@ -246,6 +385,7 @@ private static Object adapteeNonWrapper(final Object wrapper) {
     /**
      * Unwraps the given wrapper instance with {@code null} check.
      */
+    @Contract(pure = true)
     private static Object unwrapNonNull(final Object wrapper) {
         Object unwrap = ((Wrapper<?>) wrapper).unwrap();
         Supplier<String> msg = () -> "unwrap of Wrapper(" + wrapper.getClass().getName() + ") is null";
diff --git a/src/test/java/io/foldright/demo/Demo.java b/src/test/java/io/foldright/demo/Demo.java
index 6bc4901..03aaab2 100644
--- a/src/test/java/io/foldright/demo/Demo.java
+++ b/src/test/java/io/foldright/demo/Demo.java
@@ -1,10 +1,8 @@
 package io.foldright.demo;
 
-import io.foldright.inspectablewrappers.Inspector;
-
 import java.util.concurrent.Executor;
 
-import static io.foldright.inspectablewrappers.Inspector.containsInstanceOnWrapperChain;
+import static io.foldright.inspectablewrappers.Inspector.containsInstanceTypeOnWrapperChain;
 import static io.foldright.inspectablewrappers.Inspector.getAttachmentFromWrapperChain;
 
 
@@ -17,7 +15,7 @@ public static void main(String[] args) {
         ////////////////////////////////////////
 
         System.out.println("Is executor lazy? " +
-                containsInstanceOnWrapperChain(executor, LazyExecutorWrapper.class));
+                containsInstanceTypeOnWrapperChain(executor, LazyExecutorWrapper.class));
         // print true
 
         String busy = getAttachmentFromWrapperChain(executor, "busy");
diff --git a/src/test/java/io/foldright/demo/integration/IntegrationDemo.java b/src/test/java/io/foldright/demo/integration/IntegrationDemo.java
index 21fa0d6..06f7505 100644
--- a/src/test/java/io/foldright/demo/integration/IntegrationDemo.java
+++ b/src/test/java/io/foldright/demo/integration/IntegrationDemo.java
@@ -8,7 +8,7 @@
 
 import java.util.concurrent.Executor;
 
-import static io.foldright.inspectablewrappers.Inspector.containsInstanceOnWrapperChain;
+import static io.foldright.inspectablewrappers.Inspector.containsInstanceTypeOnWrapperChain;
 import static io.foldright.inspectablewrappers.Inspector.getAttachmentFromWrapperChain;
 
 
@@ -21,7 +21,7 @@ public static void main(String[] args) {
         ////////////////////////////////////////
 
         System.out.println("Is executor ExistedExecutorWrapper? " +
-                containsInstanceOnWrapperChain(executor, ExistedExecutorWrapper.class));
+                containsInstanceTypeOnWrapperChain(executor, ExistedExecutorWrapper.class));
         // print true
         String adaptAttachment = getAttachmentFromWrapperChain(executor, "adapted-existed-executor-wrapper-msg");
         System.out.println("Adapted existed executor wrapper msg: " + adaptAttachment);
diff --git a/src/test/java/io/foldright/demo/integration/IntegrationDemoUsingWrapperAdapterUtils.java b/src/test/java/io/foldright/demo/integration/IntegrationDemoUsingWrapperAdapterUtils.java
index 9d0c227..7c5e9b0 100644
--- a/src/test/java/io/foldright/demo/integration/IntegrationDemoUsingWrapperAdapterUtils.java
+++ b/src/test/java/io/foldright/demo/integration/IntegrationDemoUsingWrapperAdapterUtils.java
@@ -7,7 +7,7 @@
 
 import java.util.concurrent.Executor;
 
-import static io.foldright.inspectablewrappers.Inspector.containsInstanceOnWrapperChain;
+import static io.foldright.inspectablewrappers.Inspector.containsInstanceTypeOnWrapperChain;
 import static io.foldright.inspectablewrappers.Inspector.getAttachmentFromWrapperChain;
 
 
@@ -20,7 +20,7 @@ public static void main(String[] args) {
         ////////////////////////////////////////
 
         System.out.println("Is executor ExistedExecutorWrapper? " +
-                containsInstanceOnWrapperChain(executor, ExistedExecutorWrapper.class));
+                containsInstanceTypeOnWrapperChain(executor, ExistedExecutorWrapper.class));
         // print true
         String adaptAttachment = getAttachmentFromWrapperChain(executor, "adapted-existed-executor-wrapper-msg");
         System.out.println("Adapted existed executor wrapper msg: " + adaptAttachment);
diff --git a/src/test/java/io/foldright/inspectablewrappers/WrapperAdapterTest.kt b/src/test/java/io/foldright/inspectablewrappers/WrapperAdapterTest.kt
index 9d2f6e9..5074a5c 100644
--- a/src/test/java/io/foldright/inspectablewrappers/WrapperAdapterTest.kt
+++ b/src/test/java/io/foldright/inspectablewrappers/WrapperAdapterTest.kt
@@ -1,6 +1,6 @@
 package io.foldright.inspectablewrappers
 
-import io.foldright.inspectablewrappers.Inspector.containsInstanceOnWrapperChain
+import io.foldright.inspectablewrappers.Inspector.containsInstanceTypeOnWrapperChain
 import io.foldright.inspectablewrappers.Inspector.getAttachmentFromWrapperChain
 import io.foldright.inspectablewrappers.utils.AttachableDelegate
 import io.kotest.assertions.fail
@@ -25,10 +25,10 @@ class WrapperAdapterTest : FunSpec({
         .let(::ChattyExecutorWrapper)
 
     test("WrapperAdapter") {
-        containsInstanceOnWrapperChain(executorChain, ExistedExecutorWrapper::class.java).shouldBeTrue()
-        containsInstanceOnWrapperChain(executorChain, ExistedExecutorWrapperAdapter::class.java).shouldBeTrue()
-        containsInstanceOnWrapperChain(executorChain, ChattyExecutorWrapper::class.java).shouldBeTrue()
-        containsInstanceOnWrapperChain(executorChain, ExecutorService::class.java).shouldBeFalse()
+        containsInstanceTypeOnWrapperChain(executorChain, ExistedExecutorWrapper::class.java).shouldBeTrue()
+        containsInstanceTypeOnWrapperChain(executorChain, ExistedExecutorWrapperAdapter::class.java).shouldBeTrue()
+        containsInstanceTypeOnWrapperChain(executorChain, ChattyExecutorWrapper::class.java).shouldBeTrue()
+        containsInstanceTypeOnWrapperChain(executorChain, ExecutorService::class.java).shouldBeFalse()
 
         val value: String? = getAttachmentFromWrapperChain(executorChain, ADAPTED_MSG_KEY)
         value shouldBe ADAPTED_MSG_VALUE
@@ -62,11 +62,11 @@ class WrapperAdapterTest : FunSpec({
                 " is an instance of Wrapper, adapting a Wrapper to a Wrapper is UNNECESSARY"
 
         shouldThrow<IllegalStateException> {
-            containsInstanceOnWrapperChain(chain, ExecutorService::class.java)
+            containsInstanceTypeOnWrapperChain(chain, ExecutorService::class.java)
         }.message shouldBe errMsg
         // first instance is ok, not trigger the check logic yet...
-        containsInstanceOnWrapperChain(chain, Executor::class.java).shouldBeTrue()
-        containsInstanceOnWrapperChain(chain, ChattyExecutorWrapperAdapter::class.java).shouldBeTrue()
+        containsInstanceTypeOnWrapperChain(chain, Executor::class.java).shouldBeTrue()
+        containsInstanceTypeOnWrapperChain(chain, ChattyExecutorWrapperAdapter::class.java).shouldBeTrue()
 
         shouldThrow<IllegalStateException> {
             getAttachmentFromWrapperChain(chain, "k1")
diff --git a/src/test/java/io/foldright/inspectablewrappers/WrapperTest.kt b/src/test/java/io/foldright/inspectablewrappers/WrapperTest.kt
index 1adff05..54a4dae 100644
--- a/src/test/java/io/foldright/inspectablewrappers/WrapperTest.kt
+++ b/src/test/java/io/foldright/inspectablewrappers/WrapperTest.kt
@@ -1,6 +1,6 @@
 package io.foldright.inspectablewrappers
 
-import io.foldright.inspectablewrappers.Inspector.containsInstanceOnWrapperChain
+import io.foldright.inspectablewrappers.Inspector.containsInstanceTypeOnWrapperChain
 import io.foldright.inspectablewrappers.Inspector.getAttachmentFromWrapperChain
 import io.foldright.inspectablewrappers.utils.AttachableDelegate
 import io.kotest.assertions.fail
@@ -21,9 +21,9 @@ class WrapperTest : FunSpec({
         .let(::ChattyExecutorWrapper)
 
     test("wrapper") {
-        containsInstanceOnWrapperChain(executorChain, LazyExecutorWrapper::class.java).shouldBeTrue()
-        containsInstanceOnWrapperChain(executorChain, ChattyExecutorWrapper::class.java).shouldBeTrue()
-        containsInstanceOnWrapperChain(executorChain, ExecutorService::class.java).shouldBeFalse()
+        containsInstanceTypeOnWrapperChain(executorChain, LazyExecutorWrapper::class.java).shouldBeTrue()
+        containsInstanceTypeOnWrapperChain(executorChain, ChattyExecutorWrapper::class.java).shouldBeTrue()
+        containsInstanceTypeOnWrapperChain(executorChain, ExecutorService::class.java).shouldBeFalse()
 
         val value: String? = getAttachmentFromWrapperChain(executorChain, "busy")
         value shouldBe "very, very busy!"
@@ -49,12 +49,12 @@ class WrapperTest : FunSpec({
         }.message shouldBe "key is null"
     }
 
-    test("inspect last instance - containsInstanceOnWrapperChain") {
+    test("inspect last instance - containsInstanceTypeOnWrapperChain") {
         val pool = Executors.newCachedThreadPool()
-        containsInstanceOnWrapperChain(pool, ExecutorService::class.java).shouldBeTrue()
+        containsInstanceTypeOnWrapperChain(pool, ExecutorService::class.java).shouldBeTrue()
 
         val chatty = ChattyExecutorWrapper(pool)
-        containsInstanceOnWrapperChain(chatty, ExecutorService::class.java).shouldBeTrue()
+        containsInstanceTypeOnWrapperChain(chatty, ExecutorService::class.java).shouldBeTrue()
     }
 
     test("inspect last instance - getAttachmentFromWrapperChain") {
diff --git a/src/test/java/io/foldright/inspectablewrappers/utils/WrapperAdapterUtilsTest.kt b/src/test/java/io/foldright/inspectablewrappers/utils/WrapperAdapterUtilsTest.kt
index d3a1141..2689b3c 100644
--- a/src/test/java/io/foldright/inspectablewrappers/utils/WrapperAdapterUtilsTest.kt
+++ b/src/test/java/io/foldright/inspectablewrappers/utils/WrapperAdapterUtilsTest.kt
@@ -36,9 +36,9 @@ class WrapperAdapterUtilsTest : FunSpec({
             }
             .let(::ChattyExecutorWrapper)
 
-        Inspector.containsInstanceOnWrapperChain(chain, ExistedExecutorWrapper::class.java).shouldBeTrue()
-        Inspector.containsInstanceOnWrapperChain(chain, ChattyExecutorWrapper::class.java).shouldBeTrue()
-        Inspector.containsInstanceOnWrapperChain(chain, ExecutorService::class.java).shouldBeFalse()
+        Inspector.containsInstanceTypeOnWrapperChain(chain, ExistedExecutorWrapper::class.java).shouldBeTrue()
+        Inspector.containsInstanceTypeOnWrapperChain(chain, ChattyExecutorWrapper::class.java).shouldBeTrue()
+        Inspector.containsInstanceTypeOnWrapperChain(chain, ExecutorService::class.java).shouldBeFalse()
 
         val value: String? = Inspector.getAttachmentFromWrapperChain(chain, ADAPTED_MSG_KEY)
         value shouldBe ADAPTED_MSG_VALUE
@@ -60,9 +60,9 @@ class WrapperAdapterUtilsTest : FunSpec({
             }
             .let(::ChattyExecutorWrapper)
 
-        Inspector.containsInstanceOnWrapperChain(chain, ExistedExecutorWrapper::class.java).shouldBeTrue()
-        Inspector.containsInstanceOnWrapperChain(chain, ChattyExecutorWrapper::class.java).shouldBeTrue()
-        Inspector.containsInstanceOnWrapperChain(chain, ExecutorService::class.java).shouldBeFalse()
+        Inspector.containsInstanceTypeOnWrapperChain(chain, ExistedExecutorWrapper::class.java).shouldBeTrue()
+        Inspector.containsInstanceTypeOnWrapperChain(chain, ChattyExecutorWrapper::class.java).shouldBeTrue()
+        Inspector.containsInstanceTypeOnWrapperChain(chain, ExecutorService::class.java).shouldBeFalse()
 
         Inspector.getAttachmentFromWrapperChain<Executor, String, String?>(chain, "not existed").shouldBeNull()