How to allocate/support fractional value to new extended resource on a Node?

Hi,

Kubernetes version: 1.21

I am working on new extended resource on a Node
Ref:

I have question how can I support fractional value thorough plugin api?
e.g. ```
example.com/dongle: 2.5


Does that require to make changes in https://github.com/kubernetes/kubelet/blob/master/pkg/apis/deviceplugin/v1beta1/api.pb.go? 
I am new to this concept trying to understand it more better.

Thanks in advance.