return !(isFinal()
          || isPrivate()
          || isStatic()
          || Modifier.isFinal(getDeclaringClass().getModifiers()));
    }

    @Override
    public final boolean isVarArgs() {
      return method.isVarArgs();
    }
  }

  static class ConstructorInvokable<T> extends Invokable<T, T> {

    final Constructor<?> constructor;

    ConstructorInvokable(Constructor<?> constructor) {

    assertFalse(delegate.isVarArgs());
  }

  public void testPrivateFinalInstanceMethod_isOverridable() throws Exception {
    Invokable<?, ?> delegate = Prepender.method("privateFinalMethod");
    assertTrue(delegate.isPrivate());
    assertTrue(delegate.isFinal());
    assertFalse(delegate.isOverridable());
    assertFalse(delegate.isVarArgs());
  }