if ( litAliases!=null ) {
for (Pair<GrammarAST,GrammarAST> pair : litAliases) {
GrammarAST nameAST = pair.a;
GrammarAST litAST = pair.b;
if ( !G.stringLiteralToTypeMap.containsKey(litAST.getText()) ) {
G.defineTokenAlias(nameAST.getText(), litAST.getText());
}
else {
// oops two literal defs in two rules (within or across modes).
conflictingLiterals.add(litAST.getText());
}