
    <li><code>end_symbol</code>: Either the text that indicates the end of a fold point, or
    a function that returns whether or not <em>start_symbol</em> is a beginning fold
    point (1), an ending fold point (-1), or not a fold point at all (0).</li>
    </ul>


    <p>Usage:</p>

    <ul>
    <li><code>lex:add_fold_point(lexer.OPERATOR, '{', '}')</code></li>
    <li><code>lex:add_fold_point(lexer.KEYWORD, 'if', 'end')</code></li>
    <li><code>lex:add_fold_point(lexer.COMMENT, '#', lexer.fold_line_co