code: def play(self):
          
          if self._proc.state() == QProcess.Running:
              if self.isPlaying is False:
                  self._execute("pause")
                  self._changePlayingState(True)
          elif self._filePath is not None:
              self._kill()
              self._run(self._filePath)
              self._changePlayingState(True)
docs: Starts a playback