def respond_to?(m)
      return true if super
      return true if has_key?(key)
      return true if has_key?(key.to_s)
      has_key?(key.to_sym)
    end
def respond_to?(m)
      return true if super
      return true if has_key?(key)
      return true if has_key?(key.to_s)
      has_key?(key.to_sym)
    end
Initializes the instance to an empty Hash.
 Replaces the Object.respond_to?() method.
 @param [Symbol] m method symbol
 @return [Boolean] true for any method that matches an instance
                   variable reader, otherwise false.