(i started writing this comment before I realized that the hard part is likely getting the object back into the ES through the django test client... I'm just going to leave it here for posterity, just cause i do think it would be cleaner even though the last step isn't clear - maybe bypass the test client entirely but that seems like an unnecessary amount of work to do in addition to what's already here)

still feels like it would be better for this to be component of the resource.

sketch:

```python

class ESUserDataSource(object):
  def query(**kwargs):
     return es_wrapper(**kwargs)

class BulkUserResource(JsonResource, DomainSpecificResourceMixin):
  def __init__(self, data_source=None, *args, **kwargs):
    self.data_source = data_source or ESUserDataSource()

...

  def obj_get_list(self, bundle, **kwargs):
     ...
     users = self.data_source.query(blah)


test:

class MockUserDataSource(object):
  def query(**kwargs):
    return mock_es_wrapper(**kwargs)

# then figure out some quasi-magic way to get it into the resource
```