@Contract("null -> null")
  public static @Nullable PsiMethod getFunctionalInterfaceMethod(@Nullable PsiType functionalInterfaceType) {
    return getFunctionalInterfaceMethod(PsiUtil.resolveClassInClassTypeOnly(normalizeFunctionalType(functionalInterfaceType)));
  }
@Contract("null -> null")
  public static @Nullable PsiMethod getFunctionalInterfaceMethod(@Nullable PsiType functionalInterfaceType)