mds.run_start_given_uid(uid='some unknown uid') should fail better. Currently it fails here:
def _cache_run_start(run_start, run_start_cache):
"""De-reference and cache a RunStart document
The de-referenced Document is cached against the
ObjectId and the uid -> ObjectID mapping is stored.
Parameters
----------
run_start : dict
raw pymongo dictionary. This is expected to have
an entry `_id` with the ObjectId used by mongo.
Returns
-------
run_start : doc.Document
Document instance for this RunStart document.
The ObjectId has been stripped.
"""
> run_start = dict(run_start)
E TypeError: 'NoneType' object is not iterable
mds.run_start_given_uid(uid='some unknown uid') should fail better. Currently it fails here: