def normalize_service_argument(argument):
    """
    normalize service name and set type: $object, $variable$
    Examples:
        >>> normalize_service_argument('$Mongodb')
        ['Mongodb', 'object']
        >>> normalize_service_argument('%batch_size%')
        ['batch_size', 'variable']
    """
    if isinstance(argument, dict):
        dict_argument = {}
        for key, value in argument.items():
            if value.startswith('$'):
                dict_argument[key] = [value[1:], 'object']
            elif value.startswith('%') and value.endswith('%'):
                dict_argument[key] = [value[1:-1], 'variable']
        return [dict_argument, 'dict']
    elif type(argument) is str:
        if argument.startswith('$'):
            return [argument[1:], 'object']
        elif argument.startswith('%') and argument.endswith('%'):
            return [argument[1:-1], 'variable']
    return [None]
