def check_channel_subsystem_request(self, channel, name):
transport = channel.get_transport()<EOL>handler_class, larg, kwarg = transport._get_subsystem_handler(name)<EOL>if handler_class is None:<EOL><INDENT>return False<EOL><DEDENT>handler = handler_class(channel, name, self, *larg, **kwarg)<EOL>handler.start()<EOL>return True<EOL>
Determine if a requested subsystem will be provided to the client on
the given channel.  If this method returns ``True``, all future I/O
through this channel will be assumed to be connected to the requested
subsystem.  An example of a subsystem is ``sftp``.

The default implementation checks for a subsystem handler assigned via
`.Transport.set_subsystem_handler`.
If one has been set, the handler is invoked and this method returns
``True``.  Otherwise it returns ``False``.

.. note:: Because the default implementation uses the `.Transport` to
    identify valid subsystems, you probably won't need to override this
    method.

:param .Channel channel: the `.Channel` the pty request arrived on.
:param str name: name of the requested subsystem.
:return:
    ``True`` if this channel is now hooked up to the requested
    subsystem; ``False`` if that subsystem can't or won't be provided.