public void RemoveMustRemoveEntityAndReturnEntityEntryWhenCalled()
{
Person person = new Person {
FirstName = "Bob", LastName = "Smith"
};
MockDbSet <Person> persons = new MockDbSet <Person>(new[] { person });
Assert.Contains(persons, x => x.Id == person.Id);
EntityEntry <Person> entry = persons.Remove(person);
Assert.Equal(person.Id, entry.Entity.Id);
Assert.DoesNotContain(persons, x => x.Id == person.Id);
}