Xiang Sun

Thanks @kirsar

Can do this: ``` UserCredentials credentials = UserCredentials.newBuilder() .setClientId(clientId) .setClientSecret(clientSecret) .setRefreshToken(refreshToken) .build(); // if refresh token is invalid, throw exception AccessToken accessToken = credentials.refreshAccessToken(); GoogleAdsClient.newBuilder() .setCredentials(credentials.toBuilder().setAccessToken(accessToken).build()) .setDeveloperToken(developerToken) .setLoginCustomerId(loginCustomerId) .build(); ````