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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def ensure_dict_key(
        in_dict,
        keys,
        delimiter=DEFAULT_TARGET_DELIM,
        ordered_dict=False):
    '''
    Ensures that in_dict contains the series of recursive keys defined in keys.

    :param dict in_dict: The dict to work with.
    :param str keys: The delimited string with one or more keys.
    :param str delimiter: The delimiter to use in `keys`. Defaults to ':'.
    :param bool ordered_dict: Create OrderedDicts if keys are missing.
                              Default: create regular dicts.
    '''
    if delimiter in keys:
        a_keys = keys.split(delimiter)
    else:
        a_keys = [keys]
    dict_pointer = in_dict
    while a_keys:
        current_key = a_keys.pop(0)
        if current_key not in dict_pointer or not isinstance(dict_pointer[current_key], dict):
            dict_pointer[current_key] = OrderedDict() if ordered_dict else {}
        dict_pointer = dict_pointer[current_key]
    return in_dict