(2) Whenever any helper, assistant or employee of an employer engages any other person in the work that the helper, assistant or employee is doing for the employer, with the employer’s actual, constructive or implied knowledge, the employer shall, for all purposes of this chapter, be deemed the employer of the other person, whether the other person is paid by the helper, assistant or employee or by the employer. All persons employed by an employer in all of the employer’s several places of employment maintained within the state shall be treated as employed by a single employer for the purposes of this chapter. [Amended by 1953 c.494 §1; 1955 c.655 §2; 1959 c.405 §1; 1971 c.463 §2; 1973 c.300 §1; 1975 c.257 §1; 1981 c.77 §1; 2007 c.46 §1]