/**
     * Returns the element type if the parameter type of the method is a parameterized {@link Collection}.
     *
     * @param index
     *            The index of the parameter
     * @return The element type if the parameter type is a parameterized {@link Collection}, otherwise {@literal null}
     */
    Class<?> getElementClassOfCollection(int index);

    /**

    }
    return derivedSuites;
  }

  private static final class ReserializedListGenerator<E> implements TestListGenerator<E> {
    final OneSizeTestContainerGenerator<Collection<E>, E> gen;

    private ReserializedListGenerator(OneSizeTestContainerGenerator<Collection<E>, E> gen) {
      this.gen = gen;
    }

    @Override
    public SampleElements<E> samples() {
      return gen.samples();
    }

    @Override

   * half of that is more awkward to arrange...
   */
  private static <T> Iterable<T> iterable(Collection<T> collection) {
    // return collection::iterator;
    return new Iterable<T>() {
      @Override
      public Iterator<T> iterator() {
        return collection.iterator();
      }
    };
  }

  public void testEquals() {
    new EqualsTester()

                public boolean containsAll(Collection<?> c) {
                  return map.entrySet().containsAll(c);
                }

                @Override
                public boolean removeAll(Collection<?> c) {
                  return map.entrySet().removeAll(c);
                }

                @Override
                public boolean retainAll(Collection<?> c) {

        UnsupportedOperationException.class,
        () -> collection.removeAll(MinimalCollection.of(e0())));
    expectUnchanged();
    assertTrue(collection.contains(e0()));
  }

  /*
   * AbstractCollection fails the removeAll(null) test when the subject
   * collection is empty, but we'd still like to test removeAll(null) when we
   * can. We split the test into empty and non-empty cases. This allows us to
   * suppress only the former.

   *
   * @return set of column keys
   */
  Set<C> columnKeySet();

  /**
   * Returns a collection of all values, which may contain duplicates. Changes to the returned
   * collection will update the underlying table, and vice versa.
   *
   * @return collection of values
   */
  Collection<V> values();

  /**
   * Returns a view that associates each row key with the corresponding map from column keys to

  public void testRetainAll_duplicatesKept() {
    E[] array = createSamplesArray();
    array[1] = e0();
    collection = getSubjectGenerator().create(array);
    assertFalse(
        "containsDuplicates.retainAll(superset) should return false",
        collection.retainAll(MinimalCollection.of(createSamplesArray())));
    expectContents(array);
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.core.collection;

import java.io.Serializable;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

/**
 * {@link Set} that is case-insensitive.
 *
 * @author higa
 */

    assertEqualIgnoringOrder(getSampleElements(), asList(collection.stream().toArray()));
  }

  @CollectionFeature.Require(KNOWN_ORDER)
  public void testStreamToArrayKnownOrder() {
    assertEquals(getOrderedElements(), asList(collection.stream().toArray()));
  }

  public void testStreamCount() {
    assertEquals(getNumElements(), collection.stream().count());
  }

    assertTrue("contains(present) should return true", collection.contains(e0()));
  }

  public void testContains_no() {
    assertFalse("contains(notPresent) should return false", collection.contains(e3()));
  }

  @CollectionFeature.Require(ALLOWS_NULL_QUERIES)
  public void testContains_nullNotContainedButQueriesSupported() {
    assertFalse("contains(null) should return false", collection.contains(null));
  }