code: def labels_ticks_and_vals(self):
          
          y_ticks = defaultdict(list)
          for y, label, _, vals, color in self.iterator():
              y_ticks[label].append((y, vals, color))
          labels, ticks, vals, colors = [], [], [], []
          for label, data in y_ticks.items():
              labels.append(label)
              ticks.append(np.mean([j[0] for j in data]))
              vals.append(np.vstack([j[1] for j in data]))
              colors.append(data[0][2])  # the colors are all the same
          return labels, ticks, vals, colors
docs: Get labels, ticks, values, and colors for the variable.