gn="baseline">&nbsp;&nbsp;&nbsp;&nbsp;</td><td valign="baseline"> An object
</td></tr><tr valign="top"><td valign="baseline" nowrap><i>llrb-tree</i></td><td valign="baseline">&nbsp;&nbsp;&nbsp;&nbsp;</td><td valign="baseline"> An <a href="ref-glossary.html#id124">LLRB&nbsp;tree</a>
</td></tr><tr valign="top"><td valign="baseline" nowrap><i>default</i></td><td valign="baseline">&nbsp;&nbsp;&nbsp;&nbsp;</td><td valign="baseline"> An object (default is <code>nil</code>)
</td></tr><tr valign="top"><td valign="b