src/main/java/com/bazaarvoice/jless/parser/Parser.java
boolean resolveMixinReference(String name, ArgumentsNode arguments) {
        if (!isParserTranslationEnabled()) {
            return push(new PlaceholderNode(new SimpleNode(name)));
        }

        // Walk down the stack, looking for a scope node that knows about a given rule set
        for (Node node : getContext().getValueStack()) {
            if (!(node instanceof ScopeNode)) {
                continue;
            }

            ScopeNode scope = (ScopeNode) node;
            RuleSetNode ruleSet = scope.getRuleSet(name);

            if (ruleSet == null) {
                continue;
            }

            // Get the scope of the rule set we located and call it as a mixin
            ScopeNode ruleSetScope = NodeTreeUtils.getFirstChild(ruleSet, ScopeNode.class).callMixin(name, arguments);

            return push(ruleSetScope);
        }

        // Record error location
        throw new UndefinedMixinException(name);
    }
boolean resolveMixinReference(String name, ArgumentsNode arguments) {
        if (!isParserTranslationEnabled()) {
            return push(new PlaceholderNode(new SimpleNode(name)));
        }

        // Walk down the stack, looking for a scope node that knows about a given rule set
        for (Node node : getContext().getValueStack()) {
            if (!(node instanceof ScopeNode)) {
                continue;
            }

            ScopeNode scope = (ScopeNode) node;
            RuleSetNode ruleSet = scope.getRuleSet(name);

            if (ruleSet == null) {
                continue;
            }

            // Get the scope of the rule set we located and call it as a mixin
            ScopeNode ruleSetScope = NodeTreeUtils.getFirstChild(ruleSet, ScopeNode.class).callMixin(name, arguments);

            return push(ruleSetScope);
        }

        // Record error location
        throw new UndefinedMixinException(name);
    }
Locates the referenced mixin in one of the scope nodes on the stack. If found, the mixin's
scope is cloned and placed onto the stack in place of the mixin reference. Additionally,
any arguments are applied to the mixin's scope.