def sortedIndex(self, obj, iterator=lambda x: x):
        array = self.obj
        value = iterator(obj)
        low = 0
        high = len(array)
        while low < high:
            mid = (low + high) >> 1
            if iterator(array[mid]) < value:
                low = mid + 1
            else:
                high = mid
        return self._wrap(low)