for (int i = 0 ; i < children.size(); i++) {
String s2 = children.get(i).getValue(graph, variable, context);
if (s2 != null) {
s+= s2;
if (i < children.size()-1)
for (int i = 0 ; i < children.size(); i++) {
String s2 = children.get(i).getValue(graph, variable, context);
if (s2 != null) {
s+= s2;
if (i < children.size()-1)