def it_can_delete_elements_from_its_set(self):
doc1 = Article({'id': 1, 'name': 'doc1'})
doc2 = Article({'id': 2, 'name': 'doc2'})
doc3 = Article({'id': 3, 'name': 'doc3'})
newspaper = NewsPaper()
newspaper.collection_set= [doc1, doc2, doc3]
eq_(3, len(newspaper.collection_set))
# We remove the first element
newspaper.delete({'id': 2})
eq_(2, len(newspaper.collection_set))
eq_(True, doc1 in newspaper.collection_set)
eq_(True, doc3 in newspaper.collection_set)
eq_(False, doc2 in newspaper.collection_set)
