void checkIsE(@NullableDecl Object element) {
    checkNotNull(element);
    if (!isActuallyE(element)) {
      throw new ClassCastException("Expected an " + type + " but got " + element);
    }
  }
void checkIsE(@NullableDecl Object element) {
    checkNotNull(element);
    if (!isActuallyE(element)) {
      throw new ClassCastException("Expected an " + type + " but got " + element);
    }
  }
void checkIsE ( @ NullableDecl Object element ) { checkNotNull ( element ) ; if ( ! isActuallyE ( element ) ) { throw new ClassCastException ( "Expected an " + type + " but got " + element ) ; } }
Returns {@code element} cast to {@code E}, if it actually is a nonnull E. Otherwise, throws
either a NullPointerException or a ClassCastException as appropriate.
Returns {