new_contents: 
  class ChainedSelectAdminMixin(object):
  
      def get_form(self, request, obj=None, **kwargs):
          form = super(ChainedSelectAdminMixin, self).get_form(request, obj, **kwargs)
          if request.user:
              form.user = request.user
          return form
  
subject: Add support for getting the user in the admin site with a mixin.