def selectDialect(protocol, dialect):
    """
    Dictate a Banana dialect to use.

    @param protocol: A L{banana.Banana} instance which has not yet had a
        dialect negotiated.

    @param dialect: A L{bytes} instance naming a Banana dialect to select.
    """
    # We can't do this the normal way by delivering bytes because other setup
    # stuff gets in the way (for example, clients and servers have incompatible
    # negotiations for this step).  So use the private API to make this happen.
    protocol._selectDialect(dialect)

    Dictate a Banana dialect to use.

    @param protocol: A L{banana.Banana} instance which has not yet had a
        dialect negotiated.

    @param dialect: A L{bytes} instance naming a Banana dialect to select.
    
stackoverflow/venv/lib/python3.6/site-packages/twisted/spread/test/test_banana.py