code: def mount_point(self):
          
          try:
              return self.context.capture('stat', '--format=%m', self.directory, silent=True)
          except ExternalCommandFailed:
              return None
docs: The pathname of the mount point of :attr:`directory` (a string or :data:`None`).
  
          If the ``stat --format=%m ...`` command that is used to determine the
          mount point fails, the value of this property defaults to :data:`None`.
          This enables graceful degradation on e.g. Mac OS X whose ``stat``
          implementation is rather bare bones compared to GNU/Linux.