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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 _all_unique_texts(text, final):
 """ Compute all the possible unique texts @type text: str @param text: Text written used spin syntax @type final: list @param final: An empty list where all the unique texts will be stored @return: Nothing. The result will be in the 'final' list """

    if not char_opening in text:
        if not text in final:
            final.append(text)
        return

    stack = []
    indexes = []
    for i, c in enumerate(text):
        if c == char_closing:
            if stack[-1] == char_opening:
                start_index = indexes.pop()
                substring = '' if i == start_index + 1 else text[start_index:i + 1]
                # get some random combination
                combination = next(_choices(substring))
                new_text = text.replace(substring, combination)
                _all_unique_texts(new_text, final)
                return
        elif c == char_opening:
            stack.append(c)
            indexes.append(i)