code: def _batch_key(self, query):
      '''
      Get a unique id from a query.
      '''
      return ''.join( ['%s%s'%(k,v) for k,v in sorted(query.items())] f _batch_key(self, query):
      '''
      Get a unique id from a query.
      '''
      return ''.join( ['%s%s'%(k,v) for k,v in sorted(query.items())] )
docs: Get a unique id from a query.