def make_pid_dict( self, bdr_collection_pid, fmpro_json_path, bdr_search_api_root, output_json_path ):
     """ Creates a json file containing an accession-number to pid dict. """
     pid_finder = PidFinder( self.logger )
     pid_finder.make_dict(
         bdr_collection_pid, fmpro_json_path, bdr_search_api_root, output_json_path )
     with open( output_json_path ) as f:
         json_dict = json.loads( f.read() )
     assert sorted( json_dict.keys() ) == [ 'count', 'datetime', 'final_accession_pid_dict' ], sorted( json_dict.keys() )
     # assert json_dict['count']['count_null'] == 0  # count_null SHOULD be zero but i'm skipping this issue for now
     return