ThreeState (@NotNull ASTNode oldNode, @NotNull LighterASTNode newNode) { for (CustomLanguageASTComparator comparator : myCustomLanguageASTComparators) { ThreeState customComparatorResult = comparator.compareAST(oldNode, newNode, myTreeStructure); if (customComparatorResult != ThreeState.UNSURE) { return customComparatorResult; } } if (myCustom != null) { return myCustom.fun(oldNode, newNode, myTreeStructure); } return ThreeState.UNSURE; }