“…Jachymski in [9], merged above theories to have a generalization of the Banach contraction principle for mappings of a metric space endowed with a graph. Then, Beg et al [3] extended some results of Jachymski to multivalued mappings; other generalizations of [9] are available in [1,4,5,10,15,17,18]. For completeness, we recall that Nadler [14] first extended the Banach contraction principle to multivalued mappings; then, Nadler's fixed point theorem has been generalized and extended in several directions, see for example [2, 6, 8, 11-13, 16, 19].…”