code: def plot(self, ax=None):
      if ax is None:
          _, ax = plt.subplots()
  
      labels = list(self.counts[0].keys())
  
      x = np.arange(len(labels))
      width = 0.35
  
      name_one = self.names[0] or "first"
      name_two = self.names[1] or "second"
  
      rects1 = ax.bar(
          x - width / 2,
          self.counts[0].values(),
          width,
          label=name_one,
      )
      rects2 = ax.bar(
          x + width / 2,
          self.counts[1].values(),
          width,
          label=name_two,
      )
  
      # Add some text for labels, title and custom x-axis tick labels, etc.
      ax.set_ylabel("Count")
      ax.set_title(f"Bar plot ({name_one} and {name_two})")
      ax.set_xticks(x, labels)
      ax.legend()
  
      ax.bar_label(rects1, padding=3)
      ax.bar_label(rects2, padding=3)
  
      # remember to set these attributes
      self.ax_ = ax
      self.figure_ = ax.figure
  
      return self
  
imports: from collections import Counter
  import numpy
  import matplotlib.pyplot
  from sklearn_evaluation import __version__
  from sklearn_evaluation.plot.plot import AbstractComposedPlot, AbstractPlot
label_desc: Use image node_id 2 for calling the MyBarAdd obj's underlying member method code with example usage: obj.plot(ax) and returns: self