'Given a ResultProxy cursor as returned by connection.execute(),
return an ORM result as an iterator.
e.g.::
result = engine.execute("select * from users")
for u in session.query(User).instances(result):
print u'

def instances(self, cursor, __context=None):

    context = __context
    if (context is None):
        context = QueryContext(self)
    return loading.instances(self, cursor, context)
