code: public static MethodHandle findInstanceMethod(Class<?> clazz, String methodName,
        Class<?> expectedReturnType, Class<?>... expectedParameterTypes) {
      return findMethod(clazz, methodName, false, expectedReturnType, expectedParameterTypes);
    }
docs: Finds and returns a MethodHandle for a public instance method.
  
  @param clazz
  the class to search
  @param methodName
  the name of the method
  @param expectedReturnType
  the expected return type. If {@code null}, any return type is treated as valid.
  @param expectedParameterTypes
  expected parameter types
  @return a MethodHandle for the specified criteria. Returns {@code null} if no method exists
  with the specified criteria.