/**
* @param {!Tag}   listItem
* @param {string} text
*/
function (listItem, text)
{
// Test whether the list item is followed by a task checkbox
var pos = listItem.getPos() + listItem.getLen();
while (text.charAt(pos) === ' ')
{
++pos;
}
var str = text.substring(pos, pos + 3);
if (!/\[[ Xx]\]/.test(str))
{
return;
}

// Create a tag for the task and assign it a random ID
var taskId    = Math.random().toString(16).substring(2),
taskState = (str === '[ ]') ? 'unchecked' : 'checked',
task      = addSelfClosingTag('TASK', pos, 3);

task.setAttribute('id',    taskId);
task.setAttribute('state', taskState);

listItem.cascadeInvalidationTo(task);
}