Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:We tested different classes of corrector molecules such as corr-2b, corr-3a, corr-4a, corr-4b (Pedemonte et al., 2005), VRT-532 (Wang et al., 2006), and VRT-325 (Loo et al., 2005) for their abilities to inhibit cross-linking of L339C (TM6)/F728C (TM7).
Category: