ForApiBuilder builder = new OfflineCredentials.ForApiBuilder(
configurationHelper, OfflineCredentials.Api.DFP, oAuth2Helper);
try {
OfflineCredentials offlineCredentials = builder.fromFile("/home/user/path").build();
fail("Validation exception should have been thrown");
} catch (ValidationException e) {
assertEquals("Client secret must be set as api.dfp.clientSecret in /home/user/path."
+ "\nIf you do not have a client ID or secret, please create one in the API "
+ "console: https://code.google.com/apis/console#access", e.getMessage());