@Override
public String visit(final Composite n, final SymbolTable argu) {
final StringTemplate st = this.stg.getInstanceOf("Composite");
if (n.f1.present()) {
final NodeChoice nodeChoice = (NodeChoice) n.f1.node;
switch (nodeChoice.which) {
case 0: // pair list
st.setAttribute("pairlist", nodeChoice.choice.accept(this, argu));
break;
case 1: // expression list