code: def envelope(self, header, body):
          
          env = Element("Envelope", ns=envns)
          env.addPrefix(Namespace.xsins[0], Namespace.xsins[1])
          env.append(header)
          env.append(body)
          return env
docs: Build the B{<Envelope/>} for a SOAP outbound message.
  
          @param header: The SOAP message B{header}.
          @type header: L{Element}
          @param body: The SOAP message B{body}.
          @type body: L{Element}
          @return: The SOAP envelope containing the body and header.
          @rtype: L{Element}