diff --git a/cffu-core/src/main/java/io/foldright/cffu/CompletableFutureUtils.java b/cffu-core/src/main/java/io/foldright/cffu/CompletableFutureUtils.java
index 79d1970f..3277f2aa 100644
--- a/cffu-core/src/main/java/io/foldright/cffu/CompletableFutureUtils.java
+++ b/cffu-core/src/main/java/io/foldright/cffu/CompletableFutureUtils.java
@@ -62,10 +62,7 @@ public static CompletableFuture<Void> mRunAsync(Runnable... actions) {
      */
     public static CompletableFuture<Void> mRunAsync(Executor executor, Runnable... actions) {
         requireNonNull(executor, "executor is null");
-        requireNonNull(actions, "actions is null");
-        for (int i = 0; i < actions.length; i++) {
-            requireNonNull(actions[i], "action" + (i + 1) + " is null");
-        }
+        requireArrayAndEleNonNull("action", actions);
         return CompletableFuture.allOf(wrapActions(executor, actions));
     }
 
@@ -99,13 +96,19 @@ public static CompletableFuture<Void> mRunFastFailAsync(Runnable... actions) {
      */
     public static CompletableFuture<Void> mRunFastFailAsync(Executor executor, Runnable... actions) {
         requireNonNull(executor, "executor is null");
-        requireNonNull(actions, "actions is null");
-        for (int i = 0; i < actions.length; i++) {
-            requireNonNull(actions[i], "action" + (i + 1) + " is null");
-        }
+        requireArrayAndEleNonNull("action", actions);
         return allOfFastFail(wrapActions(executor, actions));
     }
 
+    @SafeVarargs
+    private static <T> T[] requireArrayAndEleNonNull(String varName, T... array) {
+        requireNonNull(array, varName + "s is null");
+        for (int i = 0; i < array.length; i++) {
+            requireNonNull(array[i], varName + (i + 1) + " is null");
+        }
+        return array;
+    }
+
     private static CompletableFuture<?>[] wrapActions(Executor executor, Runnable[] actions) {
         CompletableFuture<?>[] cfs = new CompletableFuture[actions.length];
         for (int i = 0; i < actions.length; i++) {
@@ -144,10 +147,7 @@ public static <T> CompletableFuture<List<T>> mSupplyAsync(Supplier<? extends T>.
     @SafeVarargs
     public static <T> CompletableFuture<List<T>> mSupplyAsync(Executor executor, Supplier<? extends T>... suppliers) {
         requireNonNull(executor, "executor is null");
-        requireNonNull(suppliers, "suppliers is null");
-        for (int i = 0; i < suppliers.length; i++) {
-            requireNonNull(suppliers[i], "supplier" + (i + 1) + " is null");
-        }
+        requireArrayAndEleNonNull("supplier", suppliers);
         return allResultsOf(wrapSuppliers(executor, suppliers));
     }
 
@@ -185,10 +185,7 @@ public static <T> CompletableFuture<List<T>> mSupplyFastFailAsync(Supplier<? ext
     @SafeVarargs
     public static <T> CompletableFuture<List<T>> mSupplyFastFailAsync(Executor executor, Supplier<? extends T>... suppliers) {
         requireNonNull(executor, "executor is null");
-        requireNonNull(suppliers, "suppliers is null");
-        for (int i = 0; i < suppliers.length; i++) {
-            requireNonNull(suppliers[i], "supplier" + (i + 1) + " is null");
-        }
+        requireArrayAndEleNonNull("supplier", suppliers);
         return allResultsOfFastFail(wrapSuppliers(executor, suppliers));
     }
 
@@ -239,10 +236,7 @@ public static <T> CompletableFuture<List<T>> mSupplyMostSuccessAsync(
             @Nullable T valueIfNotSuccess, Supplier<? extends T>... suppliers) {
         requireNonNull(executor, "executor is null");
         requireNonNull(unit, "unit is null");
-        requireNonNull(suppliers, "suppliers is null");
-        for (int i = 0; i < suppliers.length; i++) {
-            requireNonNull(suppliers[i], "supplier" + (i + 1) + " is null");
-        }
+        requireArrayAndEleNonNull("supplier", suppliers);
         return mostResultsOfSuccess(executor, timeout, unit, valueIfNotSuccess, wrapSuppliers(executor, suppliers));
     }
 
@@ -529,11 +523,7 @@ private static <T> T[] MGetSuccessNow0(@Nullable Object valueIfNotSuccess, Compl
 
     @SafeVarargs
     private static <S extends CompletionStage<?>> S[] requireCfsAndEleNonNull(S... css) {
-        requireNonNull(css, "cfs is null");
-        for (int i = 0; i < css.length; i++) {
-            requireNonNull(css[i], "cf" + (i + 1) + " is null");
-        }
-        return css;
+        return requireArrayAndEleNonNull("cf", css);
     }
 
     /**
@@ -1089,10 +1079,7 @@ public static CompletableFuture<Void> thenMRunAsync(CompletionStage<?> cf, Runna
     public static CompletableFuture<Void> thenMRunAsync(CompletionStage<?> cf, Executor executor, Runnable... actions) {
         requireNonNull(cf, "cf is null");
         requireNonNull(executor, "executor is null");
-        requireNonNull(actions, "actions is null");
-        for (int i = 0; i < actions.length; i++) {
-            requireNonNull(actions[i], "action" + (i + 1) + " is null");
-        }
+        requireArrayAndEleNonNull("action", actions);
         return toNonMinCf(cf).thenCompose(unused -> CompletableFuture.allOf(wrapActions(executor, actions)));
     }
 
@@ -1124,10 +1111,7 @@ public static CompletableFuture<Void> thenMRunFastFailAsync(
             CompletionStage<?> cf, Executor executor, Runnable... actions) {
         requireNonNull(cf, "cf is null");
         requireNonNull(executor, "executor is null");
-        requireNonNull(actions, "actions is null");
-        for (int i = 0; i < actions.length; i++) {
-            requireNonNull(actions[i], "action" + (i + 1) + " is null");
-        }
+        requireArrayAndEleNonNull("action", actions);
         return toNonMinCf(cf).thenCompose(unused -> allOfFastFail(wrapActions(executor, actions)));
     }
 
@@ -1157,10 +1141,7 @@ public static <T> CompletableFuture<Void> thenMAcceptAsync(
             CompletionStage<? extends T> cf, Executor executor, Consumer<? super T>... actions) {
         requireNonNull(cf, "cf is null");
         requireNonNull(executor, "executor is null");
-        requireNonNull(actions, "actions is null");
-        for (int i = 0; i < actions.length; i++) {
-            requireNonNull(actions[i], "action" + (i + 1) + " is null");
-        }
+        requireArrayAndEleNonNull("action", actions);
         return toNonMinCf(cf).thenCompose(v -> CompletableFuture.allOf(wrapConsumers(executor, v, actions)));
     }
 
@@ -1196,10 +1177,7 @@ public static <T> CompletableFuture<Void> thenMAcceptFastFailAsync(
             CompletionStage<? extends T> cf, Executor executor, Consumer<? super T>... actions) {
         requireNonNull(cf, "cf is null");
         requireNonNull(executor, "executor is null");
-        requireNonNull(actions, "actions is null");
-        for (int i = 0; i < actions.length; i++) {
-            requireNonNull(actions[i], "action" + (i + 1) + " is null");
-        }
+        requireArrayAndEleNonNull("action", actions);
         return toNonMinCf(cf).thenCompose(v -> allOfFastFail(wrapConsumers(executor, v, actions)));
     }
 
@@ -1240,10 +1218,7 @@ public static <T, U> CompletableFuture<List<U>> thenMApplyAsync(
             CompletionStage<? extends T> cf, Executor executor, Function<? super T, ? extends U>... fns) {
         requireNonNull(cf, "cf is null");
         requireNonNull(executor, "executor is null");
-        requireNonNull(fns, "fns is null");
-        for (int i = 0; i < fns.length; i++) {
-            requireNonNull(fns[i], "fn" + (i + 1) + " is null");
-        }
+        requireArrayAndEleNonNull("fn", fns);
         return toNonMinCf(cf).thenCompose(v -> allResultsOf(wrapFunctions(executor, v, fns)));
     }
 
@@ -1281,10 +1256,7 @@ public static <T, U> CompletableFuture<List<U>> thenMApplyFastFailAsync(
             CompletionStage<? extends T> cf, Executor executor, Function<? super T, ? extends U>... fns) {
         requireNonNull(cf, "cf is null");
         requireNonNull(executor, "executor is null");
-        requireNonNull(fns, "fns is null");
-        for (int i = 0; i < fns.length; i++) {
-            requireNonNull(fns[i], "fn" + (i + 1) + " is null");
-        }
+        requireArrayAndEleNonNull("fn", fns);
         return toNonMinCf(cf).thenCompose(v -> allResultsOfFastFail(wrapFunctions(executor, v, fns)));
     }
 
@@ -1333,10 +1305,7 @@ public static <T, U> CompletableFuture<List<U>> thenMApplyMostSuccessAsync(
             @Nullable U valueIfNotSuccess, Function<? super T, ? extends U>... fns) {
         requireNonNull(executor, "executor is null");
         requireNonNull(unit, "unit is null");
-        requireNonNull(fns, "fns is null");
-        for (int i = 0; i < fns.length; i++) {
-            requireNonNull(fns[i], "fn" + (i + 1) + " is null");
-        }
+        requireArrayAndEleNonNull("fn", fns);
         return toNonMinCf(cf).thenCompose(v -> mostResultsOfSuccess(
                 executor, timeout, unit, valueIfNotSuccess, wrapFunctions(executor, v, fns)
         ));