public static boolean hasReceiver(
     @NotNull PsiMethodReferenceExpression methodRef, @NotNull PsiMethod method) {
   return hasReceiver(methodRef, method, methodRef.getFunctionalInterfaceType());
 }
  public static String checkMethodReferenceContext(PsiMethodReferenceExpression methodRef) {
    final PsiElement resolve = methodRef.resolve();

    if (resolve == null) return null;
    return checkMethodReferenceContext(methodRef, resolve, methodRef.getFunctionalInterfaceType());
  }