docs: def current(cls):
          """Get the current event loop singleton object.
          """
          try:
              return _tls.loop
          except AttributeError:
              # create loop only for main thread
              if threading.current_thread().name == 'MainThread':
                  _tls.loop = cls()
                  return _tls.loop
              raise RuntimeError('there is no event loop created in the current thread')