public List<ParseTreeListener> getParseListeners() {
		List<ParseTreeListener> listeners = _parseListeners;
		if (listeners == null) {
			return Collections.emptyList();
		}

		return listeners;
	}
@return {@code true} if the {@link ParserRuleContext#children} list is trimmed
using the default {@link Parser.TrimToSizeListener} during the parse process.
runtime/Java/src/org/antlr/v4/runtime/Parser.java