New England Precision Grinding, Inc. (NEPG), sells precision medical parts in Massachusetts. NEPG agreed to supply Kyphon, Inc., with stylets and nozzles. NEPG contracted with Simply Surgical, LLC, to obtain the parts from Iscon Surgicals, Ltd. The contract did not mention Kyphon or require Kyphon's acceptance of the parts. Before shipping, Iscon would certify that the parts conformed to NEPG's specifications. On receiving the parts, NEPG would certify that they conformed to Kyphon's specifications. On delivery, Kyphon would also inspect the parts. After about half a dozen transactions, NEPG's payments to Simply Surgical lagged, and the seller refused to make further deliveries. NEPG filed a suit in a Massachusetts state court against Simply Surgical, alleging breach of contract. NEPG claimed that Kyphon had rejected some of the parts, which gave NEPG the right not to pay for them. Do the UCC's rules with respect to acceptance support or undercut the parties' actions? [New England Precision Grinding, Inc. v. Simply Surgical, LLC, 89 Mass.App.Ct.176, 46 N.E.3d 590 (2016)]