This class implements Bron-Kerbosch clique detection algorithm as it is described in [Samudrala
R.,Moult J.:A Graph-theoretic Algorithm for comparative Modeling of Protein Structure; J.Mol.
Biol. (1998); vol 279; pp. 287-302]
Finds all maximal cliques of the graph. A clique is maximal if it is impossible to enlarge it
by adding another vertex from the graph. Note that a maximal clique is not necessarily the
biggest clique in the graph.
Collection of cliques (each of which is represented as a Set of vertices)