code: def draw_no_data(self):
          
          no_data = self.node(
              self.graph.nodes['text_overlay'],
              'text',
              x=self.graph.view.width / 2,
              y=self.graph.view.height / 2,
              class_='no_data'
          )
          no_data.text = self.graph.no_data_text
docs: Write the no data text to the svg