code: def reset(self):
          
          self.minimum = None
          self.maximum = None
          self.start_time = None  # datetime, absolute start time
  
          self.idx_current = None
          self.idx_markers = []
          self.idx_annot = []
  
          if self.scene is not None:
              self.scene.clear()
          self.scene = None
docs: Reset the widget, and clear the scene.