@Override
  public String toString() {
    final StringBuilder sb = new StringBuilder("ReflectiveObjectInputFilterApi{");
    sb.append("apiPackage='").append(apiPackage).append('\'');
    sb.append('}');
    return sb.toString();
  }
Use reflection to look up the classes and methods for the API.
geode-serialization/src/main/java/org/apache/geode/internal/serialization/filter/ReflectiveObjectInputFilterApi.java