self.element = element

    @classmethod
    def fromstring(cls, root_name, data):
        """Initialize STSElement from name and XML string data.

        :param name: Name for XML data. Used in XML errors.
        :param data: string data to be parsed.
        :return: Returns an STSElement.
        """
        try:
            return cls(root_name, cElementTree.fromstring(data))
        except _ETREE_EXCEPTIONS as error:

            Parser for AssumeRoleWithClientGrants response

            :param data: Response data for AssumeRoleWithClientGrants request
            :return: dict
            """
            root = STSElement.fromstring(
                'AssumeRoleWithClientGrantsResponse', data)
            result = root.find('AssumeRoleWithClientGrantsResult')
            creds = result.find('Credentials')
            return dict(