public Boolean Delete <TEntity2>(TEntity2 entity) where TEntity2 : class
 {
     if (this == null)
     {
         throw new ArgumentNullException(nameof(TEntity));
     }
     lock (locker)
     {
         return(EF_Helper_DG <DataBaseEntity> .Delete(entity));
     }
 }
 public void Delete_ThreadPool <TEntity2>(TEntity2 entity) where TEntity2 : class
 {
     if (this == null)
     {
         throw new ArgumentNullException(nameof(TEntity));
     }
     lock (locker)
     {
         ThreadPool.QueueUserWorkItem(obj => EF_Helper_DG <DataBaseEntity> .Delete(entity));
     }
 }