Seems there is an issue with these changes. This is what the output of `https://www.example.com/.well-known/traffic-advice` looks like with WO 3.15.3 :
```
[\{
"user_agent": "prefetch-proxy",
"google_prefetch_proxy_eap": \{
"fraction": 1.0
\}
\}]
```
**Here is the expected output for a valid configuration**:
```
[{
"user_agent": "prefetch-proxy",
"google_prefetch_proxy_eap": {
"fraction": 1.0
}
}]
```