public override void Load()
        {
            using (var dbContext = new ConfigurationDbContext(_nameOrConnectionString))
            {
                //dbContext.Database.EnsureCreated();
                dbContext.Database.CreateIfNotExists();
                Data = !dbContext.ConfigurationValues.Any()
                    ? CreateAndSaveDefaultValues(dbContext)
                    : dbContext.ConfigurationValues.ToDictionary(c => c.Id, c => c.Value);
            }

        }
 private static IDictionary<string, string> CreateAndSaveDefaultValues(
     ConfigurationDbContext dbContext)
 {
     var configValues = new Dictionary<string, string>
         {
             { "key1", "value_from_ef_1" },
             { "key2", "value_from_ef_2" }
         };
     dbContext.ConfigurationValues.AddRange(configValues
         .Select(kvp => new ConfigurationValue { Id = kvp.Key, Value = kvp.Value })
         .ToArray());
     dbContext.SaveChanges();
     return configValues;
 }