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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 __get_formulas(self):
 """ Gets formulas in this cell range as a tuple. If cells contain actual formulas then the returned values start with an equal sign but all values are returned. """

        array = self._get_target().getFormulaArray()
        return tuple(itertools.chain.from_iterable(array))