code: public static synchronized VarExporter forNamespace(@Nonnull final Class<?> clazz, final boolean declaredFieldsOnly) {
          return getInstance(clazz.getSimpleName(), clazz, declaredFieldsOnly);
      }
docs: Load an exporter with a specified class.
  @param clazz Class type from which variables will be exported.
  @param declaredFieldsOnly if true, will not export any variable belonging to superclasses of {@code clazz}.
  @return exporter for the given class will be created if never before accessed.