code: def _activate(self):
          
          if six.callable(self.streamer):
              # If it's a function, create the stream.
              self.stream_ = self.streamer(*(self.args), **(self.kwargs))
  
          else:
              # If it's iterable, use it directly.
              self.stream_ = iter(self.streamer)
docs: Activates the stream.