public void OnGet()
{
#region Arrange
var optionsBuilder = new DbContextOptionsBuilder <ApplicationDbContext>()
.UseInMemoryDatabase("InMemoryDb");
var mockDb = new ApplicationDbContext(optionsBuilder.Options);
var pageModel = new AddressModel(mockDb);
#endregion
#region Act
var page = pageModel.OnGet();
#endregion
#region Assert
Assert.Equal(
typeof(PageResult),
page.GetType());
#endregion
}