…call on wrapper object

Fix errors like:
```
[core][Channel grpc#39 SubChannel grpc#941] grpc: addrConn.createTransport failed to connect to ...
Err: connection error: desc = "transport: authentication handshake failed:
xds: fetching trusted roots from CertificateProvider failed: provider instance is closed"
```

…method call on wrapper object

…method call on wrapper object

…method call on wrapper object

…method call on wrapper object