### Question:
OfflineCredentials { public String getJsonKeyFilePath() { return jsonKeyFilePath; } private  OfflineCredentials(ForApiBuilder builder); HttpTransport getHttpTransport(); String getRefreshToken(); String getClientId(); String getClientSecret(); String getJsonKeyFilePath(); Credential generateCredential();  }### Answer:
@Test public void testBuilder_serviceAccount() throws Exception { OfflineCredentials offlineCredentials = new OfflineCredentials.Builder() .forApi(OfflineCredentials.Api.AD_MANAGER) .withJsonKeyFilePath("jsonKeyFilePath") .build(); assertEquals("jsonKeyFilePath", offlineCredentials.getJsonKeyFilePath()); }
@Test public void testReadPropertiesFromConfiguration_properPrefixServiceAccount() throws ValidationException { PropertiesConfiguration config = new PropertiesConfiguration(); config.setProperty("api.admanager.jsonKeyFilePath", "jsonKeyFilePathDfp"); config.setProperty("api.adwords.jsonKeyFilePath", "jsonKeyFilePathAdWords"); OfflineCredentials offlineCredentials = new OfflineCredentials.Builder() .forApi(OfflineCredentials.Api.AD_MANAGER) .from(config) .build(); assertEquals("jsonKeyFilePathDfp", offlineCredentials.getJsonKeyFilePath()); }