public void enterOuterAlt(ParserRuleContext localctx, int altNum) {
localctx.setAltNumber(altNum);
// if we have new localctx, make sure we replace existing ctx
// that is previous child of parse tree
if (_buildParseTrees && _ctx != localctx) {
ParserRuleContext parent = (ParserRuleContext) _ctx.parent;
if (parent != null) {
parent.removeLastChild();
parent.addChild(localctx);
}
}
_ctx = localctx;
}
