if (to instanceof WildcardType) {
          return; // Okay to say Foo is <?>
        }
        // Can't map from a raw class to anything other than itself or a wildcard.
        // You can't say "assuming String is Integer".
        // And we don't support "assuming String is T"; user has to say "assuming T is String".

        if (to instanceof WildcardType) {
          return; // Okay to say Foo is <?>
        }
        // Can't map from a raw class to anything other than itself or a wildcard.
        // You can't say "assuming String is Integer".
        // And we don't support "assuming String is T"; user has to say "assuming T is String".

   * whether nulls were to be permitted or forbidden, but presumably the eventual fix will be to
   * permit them, as it seems more likely that code would depend on that behavior than on the other.
   * Thus, we say the bug is in set(), which fails to support null.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static Method getSetNullSupportedMethod() {
    return getMethod(ListSetTester.class, "testSet_null");

   * whether nulls were to be permitted or forbidden, but presumably the eventual fix will be to
   * permit them, as it seems more likely that code would depend on that behavior than on the other.
   * Thus, we say the bug is in add(), which fails to support null.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static Method getAddNullSupportedMethod() {

   * whether nulls were to be permitted or forbidden, but presumably the eventual fix will be to
   * permit them, as it seems more likely that code would depend on that behavior than on the other.
   * Thus, we say the bug is in add(), which fails to support null.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static Method getAddNullSupportedMethod() {

              // We can't check that the key is mightContain() == false before the
              // put() because the key could have already been generated *or* the
              // bloom filter might say true even when it's not there (false
              // positive).
              bloomFilter.put(key);
              // False negative should *never* happen.
              assertThat(bloomFilter.mightContain(key)).isTrue();

              // We can't check that the key is mightContain() == false before the
              // put() because the key could have already been generated *or* the
              // bloom filter might say true even when it's not there (false
              // positive).
              bloomFilter.put(key);
              // False negative should *never* happen.
              assertThat(bloomFilter.mightContain(key)).isTrue();

 * of as interfaces in every important sense. Each public class such as {@link ImmutableSet} is a
 * <i>type</i> offering meaningful behavioral guarantees. This is substantially different from the
 * case of (say) {@link HashSet}, which is an <i>implementation</i>, with semantics that were
 * largely defined by its supertype.
 *
 * <p>For field types and method return types, you should generally use the immutable type (such as

 * of as interfaces in every important sense. Each public class such as {@link ImmutableSet} is a
 * <i>type</i> offering meaningful behavioral guarantees. This is substantially different from the
 * case of (say) {@link HashSet}, which is an <i>implementation</i>, with semantics that were
 * largely defined by its supertype.
 *
 * <p>For field types and method return types, you should generally use the immutable type (such as

           *
           * Also, it's nice that this approach should let us catch *only* ClassNotFoundException
           * instead of having to catch more broadly (potentially even including, say, a
           * StackOverflowError).
           */
          Class.forName("java.lang.invoke.VarHandle");
        } catch (ClassNotFoundException beforeJava9) {
          return null;
        }