docs: def bounds_handler(ctx, param, value):
      """Handle different forms of bounds."""
      retval = from_like_context(ctx, param, value)
      if retval is None and value is not None:
          try:
              value = value.strip(", []")
              retval = tuple(float(x) for x in re.split(r"[,\s]+", value))
              assert len(retval) == 4
              return retval
          except Exception:
              raise click.BadParameter(
                  "{0!r} is not a valid bounding box representation".format(value)
              )
      else:  # pragma: no cover
          return retval