def make_envelope(self, body_elements=None):
        """
        body_elements: <list> of etree.Elements or <None>
        """
        soap = self.get_soap_el_factory()
        body_elements = body_elements or []
        body = soap.Body(*body_elements)
        header = self.get_soap_header()
        if header is not None:
            elements = [header, body]
        else:
            elements = [body]
        return soap.Envelope(
            #{
            #    '{%s}encodingStyle' % namespaces.SOAP_1_2: (
            #        'http://www.w3.org/2001/12/soap-encoding')
            #},
            *elements
        )
body_elements: <list> of etree.Elements or <None>