If has $title in widgets

Should be possible like this:

<?php
    /** @see WP_Widget::widget */
        function widget( $args, $instance ) {
            extract( $args );
            $title = apply_filters( 'widget_title', $instance['title'] );
            # >>>> NEW
            if ( ! isset( $title ) OR empty( $title ) );
                return;
            # <<<< NEW
            echo $before_widget;
            if ( $title )
                echo $before_title . $title . $after_title; 
            ?>
            Hello, World!
            <?php 
            echo $after_widget;
        }
?>