Remove a specific consumer from a consumer group.
        Returns the number of pending messages that the consumer had before it
        was deleted.
        name: name of the stream.
        groupname: name of the consumer group.
        consumername: name of consumer to delete

def xgroup_delconsumer(self, name, groupname, consumername):
        """
        Remove a specific consumer from a consumer group.
        Returns the number of pending messages that the consumer had before it
        was deleted.
        name: name of the stream.
        groupname: name of the consumer group.
        consumername: name of consumer to delete
        """
        return self.execute_command('XGROUP DELCONSUMER', name, groupname,
                                    consumername)