'Identify the remote operating system and get some remote variables to
show to the user.
Internally it needs to set the following attributes which are None by
default:
self._rOS = None
self._rSystem = None
self._rUser = None
self._rSystemName = None'

def identify_os(self):

    msg = 'Shell    instances    need    to    implement    the    identify_os    method.'
    raise NotImplementedError(msg)
