static void embedCST(ParseContext context, SchemaNode node, List<Diagnostic> diagnostics) {
        if (!node.containsOtherLanguageData(LanguageType.RANK_EXPRESSION)) return;
        // Don't confuse the parser by giving empty expression
        if (CSTUtils.rangeIsEmpty(node.getRange())) return;

        node.addChild(parseRankingExpression(context, node, diagnostics));
    }
SchemaRankExpressionParser is a parser for rank epxressions, which is small part in other files
integration/schema-language-server/language-server/src/main/java/ai/vespa/schemals/schemadocument/SchemaRankExpressionParser.java