throw new UnsupportedOperationException();
  }

  /**
   * If this collection is backed by an array of its elements in insertion order, returns the offset
   * where this collection's elements end.
   */
  int internalArrayEnd() {
    throw new UnsupportedOperationException();
  }

  static <E> ImmutableCollection<E> unsafeDelegate(Collection<E> delegate) {

    throw new UnsupportedOperationException();
  }

  /**
   * If this collection is backed by an array of its elements in insertion order, returns the offset
   * where this collection's elements end.
   */
  int internalArrayEnd() {
    throw new UnsupportedOperationException();
  }

  @Override
  public abstract boolean contains(@CheckForNull Object object);

  /**

    throw new UnsupportedOperationException();
  }

  /**
   * If this collection is backed by an array of its elements in insertion order, returns the offset
   * where this collection's elements end.
   */
  int internalArrayEnd() {
    throw new UnsupportedOperationException();
  }

  @Override
  public abstract boolean contains(@CheckForNull Object object);

  /**