@Override
  public <T extends Element> Set<String> getIndexedKeys(final Class<T> elementClass) {
    makeActive();

    return getIndexedKeys(elementClass, false);
  }
@Override
  public <T extends Element> Set<String> getIndexedKeys(final Class<T> elementClass) {
    makeActive();

    return getIndexedKeys(elementClass, false);
  }
@ Override public < T extends Element > Set < String > getIndexedKeys ( final Class < T > elementClass ) { makeActive ( ) ; return getIndexedKeys ( elementClass , false ) ; }
Returns the indexed properties.

@param elementClass the element class that the index is for

@return Set of String containing the indexed properties
Returns the indexed properties .