@Override
  public <T> T getService(Class<T> type) {
    if (overriddenRegisteredClasses.containsKey(type)) {
      return type.cast(overriddenRegisteredClasses.get(type));
    }
    return baseExtensionContext.getService(type);
  }
An {@link ExtensionContext} that is able to override registered services
to provide job/service specific values.
portability-api-launcher/src/main/java/org/datatransferproject/api/launcher/DelegatingExtensionContext.java