def METHOD_NAME(args):
    """
    Generates a list from a hostname string
    * Lists are passed through
    * as are tuples (conversion in pybind11 to vector)
    * if + is found it splits the string
    """
    if isinstance(args, (list, tuple)):
        return args
    elif(isinstance(args, str)):
        hosts = args.split('+')
        hosts = [it for it in hosts if len(it)]
        return hosts
    else:
        raise ValueError("hostname needs to be string or list of strings")