visformer supports spatial feat map, update pool_size in pretrained cfg to match

timm/models/visformer.py

@@ -23,7 +23,7 @@ __all__ = ['Visformer']
 def _cfg(url='', **kwargs):
     return {
         'url': url,
-        'num_classes': 1000, 'input_size': (3, 224, 224), 'pool_size': None,
+        'num_classes': 1000, 'input_size': (3, 224, 224), 'pool_size': (7, 7),
         'crop_pct': .9, 'interpolation': 'bicubic', 'fixed_input_size': True,
         'mean': IMAGENET_DEFAULT_MEAN, 'std': IMAGENET_DEFAULT_STD,
         'first_conv': 'stem.0', 'classifier': 'head',