EPDM API: Checking If a File Is Shared

There isn’t a built in method of checking if a file is shared. (As of EPDM 2014.) Here is a small method to check whether or not a file is shared;

        private static bool IsFileShared(EdmVault5Class vault, string filename)
        {     
            if (vault == null)
                throw new ArgumentNullException("vault", "Vault cannot be null!");       
            IEdmFolder5 folder = default(IEdmFolder5);
            IEdmFile5 file = vault.GetFileFromPath(filename, out folder);
            
            if (file == null)
                return false;

            string folderPath = folder.LocalPath;
            IEdmPos5 pos = file.GetFirstFolderPosition();
            while (!pos.IsNull)
            {
                IEdmFolder5 nextFolder = file.GetNextFolder(pos);                                    
                if (nextFolder != null && nextFolder.LocalPath != folderPath)
                    return true;
            }
            return false;
        }