>
    <li><code>lexer</code>: The lexer to fold text with.</li>
    <li><code>text</code>: The text in the buffer to fold.</li>
    <li><code>start_pos</code>: The position in the buffer <em>text</em> starts at, counting from
    1.</li>
    <li><code>start_line</code>: The line number <em>text</em> starts on, counting from 1.</li>
    <li><code>start_level</code>: The fold level <em>text</em> starts on.</li>
    </ul>


    <p>Return:</p>

    <ul>
    <li>table of fold levels associated with line numbers.