def unpack_unordered_values(self, values):
        """Unpack an unordered list of values taking DelayPacking
        exceptions into account to resolve circular references .
        Used to unpack set values when order is not guaranteed by
        the serializer. See unpack_unordered_pairs()."""

        values = list(values) # To support iterators
        result = []

        # Try to unpack values more than one time to resolve cross references
        max_loop = 2
        while values and max_loop:
            next_values = []
            for value_data in values:
                blob = self._begin()
                try:
                    # try unpacking the value
                    value = self.unpack_data(value_data)
                    self._commit(blob)
                except DelayPacking:
                    self._rollback(blob)
                    # If it is delayed keep it for later
                    next_values.append(value_data)
                    continue
                result.append(value)
            values = next_values
            max_loop -= 1

        if values:
            # Not all items were resolved
            raise DelayPacking()

        return result
Unpack an unordered list of values taking DelayPacking
        exceptions into account to resolve circular references .
        Used to unpack set values when order is not guaranteed by
        the serializer. See unpack_unordered_pairs().