adds a check for edge-case of a network with 0 nodes
adds a check for edge-case of a network with 0 nodes

candsvincent/edgesense,Wikitalia/edgesense,candsvincent/edgesense,Wikitalia/edgesense,candsvincent/edgesense,Wikitalia/edgesense,Wikitalia/edgesense,candsvincent/edgesense