621. Effect of change of landlord.

As from a day to be appointed1, where, at a time when a duty imposed on the landlord2 or a superior landlord, by or by virtue of any of the statutory provisions relating to service charges3 and requests for information about costs4, remains to be discharged by him, he disposes of the whole or part of his interest as landlord or superior landlord to another person5, if, despite the disposal, the landlord or superior landlord is still in a position to discharge the duty to any extent, he remains responsible for discharging it to that extent6. If the other