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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 lastIndexOf(self, item):
 """ Return the position of the last occurrence of an item in an array, or -1 if the item is not included in the array. """

        array = self.obj
        i = len(array) - 1
        if not (self._clean.isList() or self._clean.isTuple()):
            return self._wrap(-1)

        while i > -1:
            if array[i] is item:
                return self._wrap(i)
            i -= 1
        return self._wrap(-1)