docs: def visualize_explanation(explanation, label=None):
      """
      Given the output of the explain() endpoint, produces a terminal visual that plots response strength over a sequence
      """
      if not sys.version_info[:2] >= (3, 5):
        raise IndicoError("Python >= 3.5+ is required for explanation visualization")
  
      try:
        from colr import Colr as C
      except ImportError:
        raise IndicoError("Package colr >= 0.8.1 is required for explanation visualization.")
  
      cursor = 0
      text = explanation['text']
      for token in explanation.get('token_predictions'):
          try:
              class_confidence = token.get('prediction')[label]
          except KeyError:
              raise IndicoError("Invalid label: {}".format(label))
  
          if class_confidence > 0.5:
              fg_color = (255, 255, 255)
          else:
              fg_color = (0, 0, 0)
          rg_value = 255 - int(class_confidence * 255)
          token_end = token.get('token').get('end')
          token_text = text[cursor:token_end]
          cursor = token_end
          sys.stdout.write(
            str(C().b_rgb(
              rg_value, rg_value, 255
            ).rgb(
              fg_color[0], fg_color[1], fg_color[2], token_text
            ))
          )
      sys.stdout.write("\n")
      sys.stdout.flush()