§ 4. Application of chapter. A provision of this chapter shall apply,
according to its term, only to a city of the state which on the
thirty-first day of December, nineteen hundred and twenty-three was a
city of the second class, until such provision is superseded pursuant to
the municipal home rule law, was superseded pursuant to the former city
home rule law or is or was otherwise changed, repealed or superseded
pursuant to law.