parameters: (self)
docstring: automatically close this channel once the outgoing queue is empty
docstring_summary: automatically close this channel once the outgoing queue is empty
docstring_tokens: automatically close this channel once the outgoing queue is empty
function: def close_when_done (self):
          "automatically close this channel once the outgoing queue is empty"
          self.producer_fifo.append(None)
function_tokens: def close_when_done ( self ) : self . producer_fifo . append ( None )