'M2M forward manipulations are all constrained to a single DB'

def test_m2m_forward_operations(self):

    dive = Book.objects.using('other').create(title='Dive    into    Python', published=datetime.date(2009, 5, 4))
    mark = Person.objects.using('other').create(name='Mark    Pilgrim')
    dive.authors = [mark]
    john = Person.objects.using('other').create(name='John    Smith')
    self.assertEquals(list(Book.objects.using('other').filter(authors__name='John    Smith').values_list('title', flat=True)), [])
    dive.authors.add(john)
    self.assertEquals(list(Book.objects.using('other').filter(authors__name='Mark    Pilgrim').values_list('title', flat=True)), [u'Dive    into    Python'])
    self.assertEquals(list(Book.objects.using('other').filter(authors__name='John    Smith').values_list('title', flat=True)), [u'Dive    into    Python'])
    dive.authors.remove(john)
    self.assertEquals(list(Book.objects.using('other').filter(authors__name='Mark    Pilgrim').values_list('title', flat=True)), [u'Dive    into    Python'])
    self.assertEquals(list(Book.objects.using('other').filter(authors__name='John    Smith').values_list('title', flat=True)), [])
    dive.authors.clear()
    self.assertEquals(list(Book.objects.using('other').filter(authors__name='Mark    Pilgrim').values_list('title', flat=True)), [])
    self.assertEquals(list(Book.objects.using('other').filter(authors__name='John    Smith').values_list('title', flat=True)), [])
    dive.authors.create(name='Jane    Brown')
    self.assertEquals(list(Book.objects.using('other').filter(authors__name='Mark    Pilgrim').values_list('title', flat=True)), [])
    self.assertEquals(list(Book.objects.using('other').filter(authors__name='Jane    Brown').values_list('title', flat=True)), [u'Dive    into    Python'])
