docs: def _disp_width(self, pwcs, n=None):
          """
          A wcswidth that never gives -1. Copying existing code is evil, but..
          github.com/jquast/wcwidth/blob/07cea7f/wcwidth/wcwidth.py#L182-L204
          """
          # pylint: disable=C0103
          #         Invalid argument name "n"
          # TODO: Shall we consider things like ANSI escape seqs here?
          #       We can implement some ignore-me segment like those wrapped by
          #       \1 and \2 in readline too.
          end = len(pwcs) if n is None else n
          idx = slice(0, end)
          width = 0
          for char in pwcs[idx]:
              width += max(0, wcwidth(char))
          return width