def write_history_file(filename): 
    Readline.writeHistoryFile(filename)
Create a command to return a field from the Bridge's external_ids
dataset/ETHPy150Open babble/babble/include/jython/Lib/readline.py/write_history_file--crossover with--dataset/ETHPy150Open openstack/neutron/neutron/agent/ovsdb/api.py/API.br_get_external_id