def _command(self, event, command, *args, **kwargs):
        """
        Context state controller.

        Check whether the transition is possible or not, it executes it and
        triggers the Hooks with the pre_* and post_* events.

        @param event: (str) event generated by the command.
        @param command: (virDomain.method) state transition to impose.
        @raise: RuntimeError.

        """
        self._assert_transition(event)
        self.trigger('pre_%s' % event, **kwargs)
        self._execute_command(command, *args)
        self.trigger('post_%s' % event, **kwargs)
Context state controller.

        Check whether the transition is possible or not, it executes it and
        triggers the Hooks with the pre_* and post_* events.

        @param event: (str) event generated by the command.
        @param command: (virDomain.method) state transition to impose.
        @raise: RuntimeError.