Test case for backend not defined; remove unreachable code Verify that error is raised in configuration.py if backend is not defined in config.ini. Remove unreachable code from instance.py that detects that backend is not defined. It hasn't been reachable since version 1.6.1 because the configuration.py module made the backend option mandatory. Hence configuration.py raises the error and never passes control back to the unreachable code.

try:
    # Python 3+.
    from xmlrpc import client, server
    server.SimpleXMLRPCDispatcher
except (ImportError, AttributeError):
    # Python 2.
    import xmlrpclib as client  # noqa: F401
    import SimpleXMLRPCServer as server