* {@code final} keyword. For example, it could be private, or it could be declared by a final
   * class. To tell whether a method is overridable, use {@link Invokable#isOverridable}.
   */
  public final boolean isFinal() {
    return Modifier.isFinal(getModifiers());
  }

  /** Returns true if the method is abstract. */
  public final boolean isAbstract() {