//Change in Python 3.3: yield from 'xxx'
//yield_expr: 'yield' [yield_arg]
final public void yield_expr() throws ParseException {
/*@bgen(jjtree) yield_expr */
SimpleNode jjtn000 = builder.openNode(JJTYIELD_EXPR);
boolean jjtc000 = true;
jjtree.openNodeScope(jjtn000);
jjtreeOpenNodeScope(jjtn000);
Token spStr;
boolean isYieldFrom = false;