docs: def send_file(self, file_name, remote_destination=None, **kwargs):
          """Send a file to a remote host with rsync.
  
          Args:
              file_name (str): The relative location of the file on the local
                  host.
  
              remote_destination (str): The destination for the file on the remote
                  host. If `None`, will be assumed to be the same as
                  **file_name**. Default `None`.
  
              **kwargs: Passed to ``SubprocessTask``'s init method.
  
          Return:
              ``pyrem.task.SubprocessTask``: The resulting task.
          """
          if not remote_destination:
              remote_destination = file_name
  
          return SubprocessTask(
              self._rsync_cmd() +
              ['-ut', file_name, '%s:%s' % (self.hostname, remote_destination)],
              **kwargs)