def getAttributeValue(self, index):
        """
        This function is only used to look up strings
        All other work is done by
        :func:`~androguard.core.bytecodes.axml.format_value`
        # FIXME should unite those functions
        :param index: index of the attribute
        :return:
        """
        offset = self._get_attribute_offset(index)
        valueType = self.m_attributes[offset + ATTRIBUTE_IX_VALUE_TYPE]
        if valueType == TYPE_STRING:
            valueString = self.m_attributes[offset + ATTRIBUTE_IX_VALUE_STRING]
            return self.sb[valueString]
        return ''