}
// check if network already created
if (pairFileNetwork.containsKey(pairFile)) {
pairFileNetwork.get(pairFile)
.addEdge(pairUser.toStringUserAndUser2(), pairUser.getUser(), pairUser.getUser2(), EdgeType.DIRECTED);
} else {
DirectedSparseGraph<String, String> graphMulti
= new DirectedSparseGraph<>();
graphMulti.addEdge(pairUser.toStringUserAndUser2(), pairUser.getUser(), pairUser.getUser2(), EdgeType.DIRECTED);
pairFileNetwork.put(pairFile, graphMulti);