code: def determine_emitter(self, request, *args, **kwargs):
          
          em = kwargs.pop('emitter_format', None)
  
          if not em:
              em = request.GET.get('format', 'json')
  
          return em
docs: Function for determening which emitter to use
          for output. It lives here so you can easily subclass
          `Resource` in order to change how emission is detected.
  
          You could also check for the `Accept` HTTP header here,
          since that pretty much makes sense. Refer to `Mimer` for
          that as well.