code: def _call_pip(self, name=None, prefix=None, extra_args=None,
                    callback=None):
          
          cmd_list = self._pip_cmd(name=name, prefix=prefix)
          cmd_list.extend(extra_args)
  
          process_worker = ProcessWorker(cmd_list, pip=True, callback=callback)
          process_worker.sig_finished.connect(self._start)
          self._queue.append(process_worker)
          self._start()
  
          return process_worker
docs: Call pip in QProcess worker.