private static void updateChecksum(MurmurHashChecksum checksum, Token token) {
		if (token == null) {
			checksum.update(0);
			return;
		}

		updateChecksum(checksum, token.getStartIndex());
		updateChecksum(checksum, token.getStopIndex());
		updateChecksum(checksum, token.getLine());
		updateChecksum(checksum, token.getCharPositionInLine());
		updateChecksum(checksum, token.getType());
		updateChecksum(checksum, token.getChannel());
	}
This method is separate from {@link #parse1} so the first pass can be distinguished when analyzing
 profiler results.
tool-testsuite/test/org/antlr/v4/test/tool/TestPerformance.java