view.decEdgesCountTotal(1);
boolean mutual = !edge.isSelfLoop() && node.getEdgesOutTree().hasNeighbour(source);
if (node.isEnabled() && source.isEnabled()) {
view.decEdgesCountEnabled(1);
node.decEnabledInDegree();
source.decEnabledOutDegree();
if (mutual) {
source.decEnabledMutualDegree();
node.decEnabledMutualDegree();
view.decMutualEdgesEnabled(1);
}