code: def _setup(self):
          
          # Expands ~user in queue
          if self.queue.path[0:1] == b'/':
              queue = self.queue
          else:
              if self.queue.path[0:1] == b'~':
                  output = self.check_output('echo %s' %
                                             escape_queue(self.queue))
                  queue = PosixPath(output.rstrip(b'\r\n'))
              else:
                  output = self.check_output('pwd')
                  queue = PosixPath(output.rstrip(b'\r\n')) / self.queue
              logger.debug("Resolved to %s", queue)
  
          # Select runtime
          if not self.setup_runtime:
              # Autoselect
              if self._call('which qsub', False)[0] == 0:
                  logger.debug("qsub is available, using runtime 'pbs'")
                  runtime = 'pbs'
              else:
                  logger.debug("qsub not found, using runtime 'default'")
                  runtime = 'default'
          else:
              runtime = self.setup_runtime
  
          if self.need_runtime is not None and runtime not in self.need_runtime:
              raise ValueError("About to setup runtime %s but that wouldn't "
                               "match explicitely allowed runtimes" % runtime)
  
          logger.info("Installing runtime %s%s at %s",
                      runtime,
                      "" if self.setup_runtime else " (auto)",
                      self.queue)
  
          # Uploads runtime
          scp_client = self.get_scp_client()
          filename = pkg_resources.resource_filename('tej',
                                                     'remotes/%s' % runtime)
          scp_client.put(filename, str(queue), recursive=True)
          logger.debug("Files uploaded")
  
          # Runs post-setup script
          self.check_call('/bin/sh %s' % shell_escape(queue / 'commands/setup'))
          logger.debug("Post-setup script done")
  
          self._queue = queue
          return queue
docs: Actually installs the runtime.