code: def active(self):
          
  
          context = self._get_context()
          if not context:
              return super(TornadoScopeManager, self).active
  
          return context.active
docs: Return the currently active :class:`~opentracing.Scope` which
          can be used to access the currently active
          :attr:`Scope.span`.
  
          :return: the :class:`~opentracing.Scope` that is active,
              or ``None`` if not available.