@Test
public void testBuildFromPropertiesFile_withoutLoginCustomerId() throws IOException {

  // Create a properties file in the temporary folder.
  File propertiesFile = folder.newFile("ads.properties");
  // Remove the login customer ID property.
  testProperties.remove(ConfigPropertyKey.LOGIN_CUSTOMER_ID.getPropertyKey());
  try (FileWriter propertiesFileWriter = new FileWriter(propertiesFile)) {
    testProperties.store(propertiesFileWriter, null);
  }
  // Build a new client from the file.
  GoogleAdsClient client =
      GoogleAdsClient.newBuilder()
          .fromPropertiesFile(propertiesFile)
          .setTransportChannelProvider(localChannelProvider)
          .build();
  assertGoogleAdsClient(client, null, enabledGeneratedCatalog);
}