public function useCursor()
    {
        $this->files = array_merge_recursive( array( 'jqplot.cursor.js' ), $this->files );
        $this->setNestedOptVal( $this->options, 'cursor', 'show', true );
        $this->setNestedOptVal( $this->options, 'cursor', 'showTooltip', true );
        
        return $this;
    }