code: def set_y2label(self, s, delay_draw=False):
          "set plot ylabel"
          self.conf.relabel(y2label=s, delay_draw=delay_drawf set_y2label(self, s, delay_draw=False):
          "set plot ylabel"
          self.conf.relabel(y2label=s, delay_draw=delay_draw)
docs: set plot ylabel