docs: def _get_dominant_angle(lines, domination_type=MEDIAN):
      """Picks dominant angle of a set of lines.
  
      Args:
          lines: iterable of (x1, y1, x2, y2) tuples that define lines.
          domination_type: either MEDIAN or MEAN.
  
      Returns:
          Dominant angle value in radians.
  
      Raises:
          ValueError: on unknown domination_type.
      """
      if domination_type == MEDIAN:
          return _get_median_angle(lines)
      elif domination_type == MEAN:
          return _get_mean_angle(lines)
      else:
          raise ValueError('Unknown domination type provided: %s' % (
              domination_type))