add_diff_pair_length_match# Rules.add_diff_pair_length_match(name: str, tolerance: str, pairs: list[tuple[str, str]]) → Rules# Append a length-matching rule for differential pairs. Parameters: namestrRule identifier. tolerancestrMaximum allowed length difference with unit, e.g. "0.1mm". pairslist[tuple[str, str]]List of differential pairs as tuples of Returns: RulesSelf to enable method chaining.