docs: def post(self, request, format=None):
          """ validate password change operation and return result """
          serializer_class = self.get_serializer_class()
          serializer = serializer_class(data=request.data, instance=request.user)
  
          if serializer.is_valid():
              serializer.save()
              return Response({'detail': _(u'Password successfully changed')})
  
          return Response(serializer.errors, status=400)