public function getIndent()
    {
        $leadingWhitespace = array();
        $n = 0;
        foreach( $this->lines as $line ) {
            if( !empty( $line ) ) {
                $leadingWhitespace[$n] = strlen( $line ) - strlen( ltrim( $line ) );
            }
            $n++;
        }
        return min( $leadingWhitespace );
    }