code: def _plot_depth_track(self, ax, md, kind='MD'):
          
          if kind == 'MD':
              ax.set_yscale('bounded', vmin=md.min(), vmax=md.max())
              # ax.set_ylim([md.max(), md.min()])
          elif kind == 'TVD':
              tvd = self.location.md2tvd(md)
              ax.set_yscale('piecewise', x=tvd, y=md)
              # ax.set_ylim([tvd.max(), tvd.min()])
          else:
              raise Exception("Kind must be MD or TVD")
  
          for sp in ax.spines.values():
              sp.set_color('gray')
  
          if ax.is_first_col():
              pad = -10
              ax.spines['left'].set_color('none')
              ax.yaxis.set_ticks_position('right')
              for label in ax.get_yticklabels():
                  label.set_horizontalalignment('right')
          elif ax.is_last_col():
              pad = -10
              ax.spines['right'].set_color('none')
              ax.yaxis.set_ticks_position('left')
              for label in ax.get_yticklabels():
                  label.set_horizontalalignment('left')
          else:
              pad = -30
              for label in ax.get_yticklabels():
                  label.set_horizontalalignment('center')
  
          ax.tick_params(axis='y', colors='gray', labelsize=12, pad=pad)
          ax.set_xticks([])
  
          ax.set(xticks=[])
          ax.depth_track = True
  
          return ax
docs: Private function. Depth track plotting.
  
          Args:
              ax (ax): A matplotlib axis.
              md (ndarray): The measured depths of the track.
              kind (str): The kind of track to plot.
  
          Returns:
              ax.