This function is called when setting a filter for this generated
     * property. Returning null from this function causes
     * GeneratedPropertyContainer to discard the filter and not use it.
     * 
     * By default this function throws UnsupportedFilterException.
This function is called when setting a filter for this generated
     * property. Returning null from this function causes
     * GeneratedPropertyContainer to discard the filter and not use it.
     * 
     * By default this function throws UnsupportedFilterException. | PropertyValueGenerator.java