A licensee is de fined by section 2(j) to mean: " . a person licensed under part II of the Electricity Act to supply electricity energy, or a person who has obtained sanction under section 28 of that Act to engage in the business of supplying electricity and in relation to an undertaking taken over.or an undertaking which has vested in the Government under section 4 the person, who was the licen see at the time the undertaking was taken over or vested in the Government, as the case may be, and includes the successorin interest of any such person;" The State Electricity Board stepped into the shoes of the licensee on behalf of the State, to discharge all the existing obligations of the licensee, arising out of past transactions, and, for this reason, became entitled to the benefits of all contracts, whether they had accrued in the past or were to arise in future, which existed at the time of the taking over of the undertaking.