String (@NotNull String modifier, @NotNull PsiModifierList modifierList) { PsiElement parent = modifierList.getParent(); if (parent == null) return null; Map<String, Set<String>> incompatibleModifierMap = getIncompatibleModifierMap(parent); return incompatibleModifierMap == null ? null : getIncompatibleModifier(modifier, modifierList, incompatibleModifierMap); }