Issue: William owns a building that is leased to Lesters Machine Shop. Lester requests that William rewire the building for new equipment Lester plans to purchase. The wiring would cost about $4,000, but would not increase the value of the building because its only use is in the connection with the specialized equipment. Rather than lose Lester as a lessee, William agrees to forgo one months rent of $1,000 if Lester will pay for the wiring. Because Lester does not want to move, he agrees. What amount, if any, must William include in gross income?

A partial list of research sources is

Sec. 109

Reg. Sec. 1.109-1

CIR v. Grace H. Cunningham, 2 AFTR 2d 5511, 58-2 USTC 9771 (9th Cir. 1958)

Please make it 2 pages please.