public async void TestUpdate()
{
// Arrange
var gateway = new Gateway {
Id = 1, Name = "wee", IPv4 = "192.168.4.12", SerialNumber = "sdsd"
};
var options = new DbContextOptionsBuilder <GatewayDbContext>().UseInMemoryDatabase("gateway_test_update");
var db = new GatewayDbContext(options.Options);
// db.RemoveRange(db.Gateways);
// await db.SaveChangesAsync();
db.Add(gateway);
db.SaveChanges();
var repo = new GatewayRepository(db);
// Act
gateway.IPv4 = "192.168.4.13";
var result = await repo.Update(gateway);
// Assert
Assert.True(result.Status);
Assert.Equal("192.168.4.13", ((Gateway)result.Entity).IPv4);
}