public ResponseBuilder addDirective(Directive directive) {
        if (directiveList == null) {
            directiveList = new ArrayList<>();
        }
        directiveList.add(directive);

        return this;
    }
public ResponseBuilder addDirective ( Directive directive ) { if ( directiveList == null ) { directiveList = new ArrayList < > ( ) ; } directiveList . add ( directive ) ; return this ; }
Adds a given {@link Directive} to the response.

@param directive directive to send with the response back to the Alexa device
@return response builder