def valid?
      return false if @action.nil?
      action_validator = EnumAttributeValidator.new('String', ["COMPLETE", "CANCEL", "REFUND"])
      return false unless action_validator.valid?(@action)
      return true
    end
def valid?
      return false if @action.nil?
      action_validator = EnumAttributeValidator.new('String', ["COMPLETE", "CANCEL", "REFUND"])
      return false unless action_validator.valid?(@action)
      return true
    end
Check to see if the all the properties in the model are valid
 @return true if the model is valid