storing only_head flag

cvmodelz/classifiers/base.py

@@ -17,6 +17,7 @@ class Classifier(chainer.Chain):
 		only_head: bool = False,
 		):
 		super().__init__()
+		self._only_head = only_head
 		self.layer_name = layer_name or model.clf_layer_name
 		self.loss_func = loss_func