@Override
                             public void onError(Throwable t) {
                                 causeRef.set(t);
                                 completed.set(true);
                             }
Reproduce a race case about an endpoint selection that occurs if the following two conditions are met.
1) An EndpointGroup resolved and has non-empty endpoints when creating a ArmeriaClientCall.
2) The endpoints in the EndpointGroup become empty when the ArmeriaClientCall initializing context.
grpc/src/test/java/com/linecorp/armeria/client/grpc/LazyDynamicEndpointGroupTest.java