in jdbc-grpc-client/src/main/java/org/apache/kyuubi/grpc/client/SimpleBlockingJdbcClient.java [306:313]
public DirectStatusResp setReadOnly(String connectionId, boolean readOnly) {
SetReadOnlyReq.Builder builder = SetReadOnlyReq.newBuilder();
SetReadOnlyReq req = builder
.setConnectionId(ConnectionHandle.newBuilder().setId(connectionId).build())
.setReadOnly(readOnly)
.build();
return connectionBlockingStub.setReadOnly(req);
}