def custom_arg(self, custom_arg):
        """Add custom args to the email

        :param value: A list of CustomArg objects or a dict of custom arg
                      key/values
        :type value: CustomArg, list(CustomArg), dict
        """
        if isinstance(custom_arg, list):
            for c in custom_arg:
                self.add_custom_arg(c)
        else:
            self.add_custom_arg(custom_arg)
def custom_arg ( self , custom_arg ) : if isinstance ( custom_arg , list ) : for c in custom_arg : self . add_custom_arg ( c ) else : self . add_custom_arg ( custom_arg )
Add custom args to the email

        :param value: A list of CustomArg objects or a dict of custom arg
                      key/values
        :type value: CustomArg, list(CustomArg), dict