docs: def postag(
      X,
      ax=None,
      tagset="penn_treebank",
      colormap=None,
      colors=None,
      frequency=False,
      **kwargs
  ):
      """
      Display a barchart with the counts of different parts of speech
      in X, which consists of a part-of-speech-tagged corpus, which the
      visualizer expects to be a list of lists of lists of (token, tag)
      tuples.
  
      Parameters
      ----------
      X : list or generator
          Should be provided as a list of documents or a generator
          that yields a list of documents that contain a list of
          sentences that contain (token, tag) tuples.
      ax : matplotlib axes
          The axes to plot the figure on.
      tagset: string
          The tagset that was used to perform part-of-speech tagging.
          Either "penn_treebank" or "universal", defaults to "penn_treebank".
          Use "universal" if corpus has been tagged using SpaCy.
      colors : list or tuple of colors
          Specify the colors for each individual part-of-speech.
      colormap : string or matplotlib cmap
          Specify a colormap to color the parts-of-speech.
      frequency: bool {True, False}, default: False
          If set to True, part-of-speech tags will be plotted according to frequency,
          from most to least frequent.
      kwargs : dict
          Pass any additional keyword arguments to the PosTagVisualizer.
  
      Returns
      -------
      ax : matplotlib axes
          Returns the axes on which the PosTagVisualizer was drawn.
      """
      # Instantiate the visualizer
      visualizer = PosTagVisualizer(
          ax=ax, tagset=tagset, colors=colors, colormap=colormap,
          frequency=frequency, **kwargs
      )
  
      # Fit and transform the visualizer (calls draw)
      visualizer.fit(X, **kwargs)
  
      # Return the axes object on the visualizer
      return visualizer