  Many authors, mainly in the context of the Bin Packing Problem with
Conflicts, used the random graph generator proposed in "Heuristics and lower
bounds for the bin packing problem with conflicts" [M. Gendreau, G. Laporte,
and F. Semet, Computers & Operations Research, 31:347-358, 2004]. In this paper
we prove that the graphs generated in this way are not arbitrary but threshold
ones. Computational results show that instances with threshold conflict graphs
are easier to solve w.r.t. instances with arbitrary conflict graphs.
