def get_stats(self, where, group_by=None):
q = Query()
for k, v in where.items():
q.where_eq(k, v)
map(q.group_by, group_by or [])
result_set = q.execute(self.collection)
results = list(result_set)
if len(results) != 1:
print(results)
raise ValueError('Sanity check failed, number of results is not 1')
""" :type result: Result """
result = results[0]
return result.stats
