TypeError: find() got an unexpected keyword argument 'slave_okay'

[oliveagle]

use mongomock to mock mongoengine Document. it works great with this exception:

from mymodel import Post
from mongomock import Connection
Post._collection = Connection().db.collection
Post._get_db = lambda: Post._collection._Collection__database

post = Post(title='hahah')
post.save()
assert( Post._collection.count() == 1)

Post.objects.first()

the last line raises:

mongoengine/queryset/queryset.pyc in _cursor(self)
   1203 
   1204             self._cursor_obj = self._collection.find(self._query,
-> 1205                                                      **self._cursor_args)
   1206             # Apply where clauses to cursor
   1207             if self._where_clause:

TypeError: find() got an unexpected keyword argument 'slave_okay'