Simplify TypeVariableName.get(TypeVariable)

There's actually no need to deal with intersection types as type mirrors,
we can just go down to the TypeParameterElement and directly get its
bounds.

src/main/java/com/squareup/javapoet/TypeVariableName.java

@@ -16,18 +16,13 @@
 package com.squareup.javapoet;
 
 import java.io.IOException;
-import java.lang.reflect.Method;
 import java.lang.reflect.Type;
 import java.lang.reflect.TypeVariable;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
-import javax.lang.model.element.NestingKind;
-import javax.lang.model.element.TypeElement;
 import javax.lang.model.element.TypeParameterElement;
-import javax.lang.model.type.DeclaredType;
-import javax.lang.model.type.TypeKind;
 import javax.lang.model.type.TypeMirror;
 
 import static com.squareup.javapoet.Util.checkArgument;
@@ -81,8 +76,13 @@ public static TypeVariableName get(String name, Type... bounds) {
 
   /** Returns type variable equivalent to {@code mirror}. */
   public static TypeVariableName get(javax.lang.model.type.TypeVariable mirror) {
-    String name = mirror.asElement().getSimpleName().toString();
-    List<? extends TypeMirror> boundsMirrors = typeVariableBounds(mirror);
+    return get((TypeParameterElement) mirror.asElement());
+  }
+
+  /** Returns type variable equivalent to {@code element}. */
+  public static TypeVariableName get(TypeParameterElement element) {
+    String name = element.getSimpleName().toString();
+    List<? extends TypeMirror> boundsMirrors = element.getBounds();
 
     List<TypeName> boundsTypeNames = new ArrayList<>();
     for (TypeMirror typeMirror : boundsMirrors) {
@@ -92,49 +92,6 @@ public static TypeVariableName get(javax.lang.model.type.TypeVariable mirror) {
     return new TypeVariableName(name, boundsTypeNames);
   }
 
-  /**
-   * Returns a list of type mirrors representing the unpacked bounds of {@code typeVariable}. This
-   * is made gnarly by the need to unpack Java 8's new IntersectionType with reflection. We don't
-   * have that type in Java 7, and {@link TypeVariable}'s array of bounds is sufficient anyway.
-   */
-  @SuppressWarnings("unchecked") // Gross things in support of Java 7 and Java 8.
-  private static List<? extends TypeMirror> typeVariableBounds(
-      javax.lang.model.type.TypeVariable typeVariable) {
-    TypeMirror upperBound = typeVariable.getUpperBound();
-
-    // On Java 8, unwrap an intersection type into its component bounds.
-    if ("INTERSECTION".equals(upperBound.getKind().name())) {
-      try {
-        Method method = upperBound.getClass().getMethod("getBounds");
-        return (List<? extends TypeMirror>) method.invoke(upperBound);
-      } catch (Exception e) {
-        throw new RuntimeException(e);
-      }
-    }
-
-    // On Java 7, intersection types exist but without explicit API. Use a (clumsy) heuristic.
-    if (upperBound.getKind() == TypeKind.DECLARED) {
-      TypeElement upperBoundElement = (TypeElement) ((DeclaredType) upperBound).asElement();
-      if (upperBoundElement.getNestingKind() == NestingKind.ANONYMOUS) {
-        List<TypeMirror> result = new ArrayList<>();
-        result.add(upperBoundElement.getSuperclass());
-        result.addAll(upperBoundElement.getInterfaces());
-        return result;
-      }
-    } else if (upperBound.getKind() == TypeKind.TYPEVAR) {
-      // Workaround for intersection types in Eclipse:
-      // Eclipse returns an equivalent TypeVariable for intersection types
-      // (wrapping the same internal TypeVariableBinding).
-      TypeParameterElement upperBoundElement =
-          (TypeParameterElement) ((javax.lang.model.type.TypeVariable) upperBound).asElement();
-      if (upperBoundElement.equals(typeVariable.asElement())) {
-        return upperBoundElement.getBounds();
-      }
-    }
-
-    return Collections.singletonList(upperBound);
-  }
-
   /** Returns type variable equivalent to {@code type}. */
   public static TypeVariableName get(TypeVariable<?> type) {
     return new TypeVariableName(type.getName(), TypeName.list(type.getBounds()));