private static void setMethodFailedError(Request req, Throwable t) {
        String msg = "Request failed due to internal error: " + t.getClass().getName() + ": " + t.getMessage();
        req.setError(ErrorCode.METHOD_FAILED, msg);
        req.returnValues().add(new StringValue(""));
    }
Rpc server for the metrics proxy.

When a new object is created after reconfiguration, it will claim ownership of the methods
in the given {@link RpcConnector}. This is ok because at the time this component is created,
all components it depends on are already created.

@author gjoranv
metrics-proxy/src/main/java/ai/vespa/metricsproxy/rpc/RpcServer.java