def respond_to?(method_name, include_private_methods = false)
      attr = "@#{method_name}"
      return super if method_name.match(/[\?!]$/) || !instance_variable_defined?(attr)
      true
    end
def respond_to?(method_name, include_private_methods = false)
      attr = "@#{method_name}"
      return super if method_name.match(/[\?!]$/) || !instance_variable_defined?(attr)
      true
    end
Overrides Object#respond_to? to also consider methods dynamically generated by {#method_missing}