“…The actual integrable model has been discussed in many papers in the literature. While it is difficult to precisely summarize the rich literature, it might be useful for readers to loosely classify the literature into: 4d N = 1 on S 1 × S 3 [14,15,16,11,12,17,24,23,28], on S 1 × S 3 Z r [13,25,21,22,29], 3d N = 2 on S 1 × S 2 [18,20,27,31], on S 3 [76,11,12] and S 3 Z r [22], 2d N = (2, 2) on S 2 [26], on T 2 [18,19,30], and 1d N = 4 on S 1 [26].…”