Update TFFs `attrs` dependency to version `21.4.0`.
@@ -55,7 +55,7 @@ DOCLINES = __doc__.split('\n')
PROJECT_NAME = 'tensorflow_federated'
REQUIRED_PACKAGES = [
'absl-py~=1.0.0',
- 'attrs~=21.2.0',
+ 'attrs~=21.4.0',
'cachetools~=3.1.1',
'dm-tree~=0.1.7',
'farmhashpy~=0.4.0',
