          self.init_files = files
          self.object = instance
  
          self._data = None
          self._files = None
          self._errors = None
  
 
</s> remove         fields = self.get_fields(nested=bool(self.opts.depth))
 </s> add         fields = self.get_fields() </s> remove         fields = self.get_fields(nested=bool(self.opts.depth))
 </s> add         fields = self.get_fields() </s> remove         fields = self.get_fields(nested=bool(self.opts.depth))
 </s> add         fields = self.get_fields() </s> remove         # TODO: Modify this so that it's called on init, and drop
        #       serialize/obj/data arguments.
        #
        #       We *could* provide a hook for dynamic fields, but
        #       it'd be nice if the default was to generate fields statically
        #       at the point of __init__
 </s> add 
        self.default_fields = self.get_default_fields()
          self.init_files = files
          self.object = instance
        self.default_fields = self.get_default_fields()
  
          self._data = None
          self._files = None
          self._errors = None
  
keep add keep keep keep keep keep
 Cache default fields per serializer instance for improved performance 
rest_framework/serializers.py