Source labels name the campaign that computed a value. They record PROVENANCE, not
membership: a value's label says which mutation list produced it, which is what makes
the number explainable, and says nothing about which benchmarks contain the mutation.

Each record has exactly one source. A definition's mutations are computed together, in
one list, against one interface -- so unlike 0.1.0 there is no precedence order here and
no conflicts to arbitrate. The unit is the SKEMPI identifier <pdb>_<group1>_<group2>.

Single-point store
========================================
323 interface definitions over 322 PDB codes / 4340 mutations

contribution by source:
  sweep_4x_round_1            4286 mutations
  3SE4_B_A_sp                   18 mutations
  3SE3_B_A_sp                   17 mutations
  3SE4_B_C_sp                   15 mutations
  2C5D_A_C_sp                    4 mutations

Multi-point store
========================================
154 interface definitions over 152 PDB codes / 1767 mutations

contribution by source:
  sweep_4x_round_1            1702 mutations
  3SE3_B_A_mp                   30 mutations
  2C5D_AB_CD_mp                 19 mutations
  2C5D_A_C_mp                   12 mutations
  3SE3_B_C_mp                    2 mutations
  3SE4_B_C_mp                    2 mutations

Absent from the store
========================================
  1KBH_A_B       [sp]    3 of    3 absent -- excluded: RepairPDB does not terminate; the complex has no usable FoldX result
  1KBH_A_B       [mp]   83 of   83 absent -- excluded: RepairPDB does not terminate; the complex has no usable FoldX result
