def __init__(self, groups=None):
        super(GroupedRequirements, self).__init__(NamedRequirements)
        self.groups = groups or self.default_groups
        self.filename = None
        self.create_default_groups()
def implementor(rpc_code, blocking=False):
    """
    RPC implementation function.
    """
    return partial(_add_implementor, rpc_code, blocking)