if (fullNodeDefinition == null) {
handleUnavailableDetachedRulesetReference(detachedRulesetReference, solvedMixinReferences);
} else {
ExpressionEvaluator expressionEvaluator = new ExpressionEvaluator(referenceScope, problemsHandler, configuration);
Expression evaluatedDetachedRuleset = expressionEvaluator.evaluate(fullNodeDefinition);
fullNodeDefinition = evaluatedDetachedRuleset;
if (evaluatedDetachedRuleset.getType() != ASTCssNodeType.DETACHED_RULESET) {
handleWrongDetachedRulesetReference(detachedRulesetReference, evaluatedDetachedRuleset, solvedMixinReferences);
} else {
DetachedRuleset detachedRuleset = (DetachedRuleset) evaluatedDetachedRuleset;