@Test
public void buildFromPropertiesFile_readsAllProperties() throws IOException {

  // Create a properties file in the temporary folder.
  File propertiesFile = folder.newFile("ads.properties");
  try (FileWriter propertiesFileWriter = new FileWriter(propertiesFile)) {
    testProperties.store(propertiesFileWriter, null);
  }
  // Build a new client from the file.
  GoogleAdsClient client =
      GoogleAdsClient.newBuilder().fromPropertiesFile(propertiesFile).build();
  assertGoogleAdsClient(client);
}