Add clarifying comment to retryGet in fetch.go.
Add clarifying comment to retryGet in fetch.go.

Qwiklabs/codelab-tools,googlecodelabs/tools,Qwiklabs/codelab-tools,Qwiklabs/codelab-tools,googlecodelabs/tools,googlecodelabs/tools,Qwiklabs/codelab-tools,googlecodelabs/tools