def list_commands(self, **kwargs):
        """
        https://docs.aws.amazon.com/systems-manager/latest/APIReference/API_ListCommands.html
        """
        commands = self._commands

        command_id = kwargs.get('CommandId', None)
        if command_id:
            commands = [self.get_command_by_id(command_id)]
        instance_id = kwargs.get('InstanceId', None)
        if instance_id:
            commands = self.get_commands_by_instance_id(instance_id)

        return {
            'Commands': [command.response_object() for command in commands]
        }