code: def toPostArgs(self):
          
          args = {}
  
          # Add namespace definitions to the output
          for ns_uri, alias in self.namespaces.items():
              if self.namespaces.isImplicit(ns_uri):
                  continue
              if alias == NULL_NAMESPACE:
                  ns_key = 'openid.ns'
              else:
                  ns_key = 'openid.ns.' + alias
              args[ns_key] = oidutil.toUnicode(ns_uri)
  
          for (ns_uri, ns_key), value in self.args.items():
              key = self.getKey(ns_uri, ns_key)
              # Ensure the resulting value is an UTF-8 encoded *bytestring*.
              args[key] = oidutil.toUnicode(value)
  
          return args
docs: Return all arguments with openid. in front of namespaced arguments.
          @return bytes