See, e.g., Operating Engineers Pension Trust v. A-C Co., 859 F.2d at 1342; Central States, Southeast and Southwest Areas Pension Fund v. Gerber Truck Serv., Inc., 854 F.2d 1074, 1080 (7th Cir. 1988), vacated on other grounds, 864 F.2d 561 (7th Cir. 1989), rehearing en banc, 870 F.2d 1148 (7th Cir. 1989); Vernau v. Bowen Enter., Inc., 648 F. Supp. 721, 724-25 (W.D.Pa. 1986); LaJiness v. Reactor Controls, Inc., 642 F. Supp. 27, 32 (E.D.Mich. 1985); Thelin v. Mitchell, 576 F. Supp. 1404, 1408-09 (N.D.Ill. 1983). Here, UMC paid the contributions before suit was filed.