The municipal officers authorized by law to contract in behalf of any city of the first class, for the lighting of its streets may, from time to time, in the manner, upon the terms and with the conditions hereinafter provided contract in behalf of such city with any corporation or corporations then supplying gas therein for a supply of gas to such city, for and during such specified period not exceeding fifteen years as shall by such municipal officers be deemed to be for the best interests of such city and of the inhabitants thereof.
New York Legal Code