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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 find_all_segment(text: str, custom_dict: Trie = None) -> List[str]: """ Get all possible segment variations :param str text: input string to be tokenized :return: returns list of segment variations """

    if not text or not isinstance(text, str):
        return []

    ww = list(_multicut(text, custom_dict=custom_dict))

    return list(_combine(ww))