/**
* Fire the onInit event to initialise the captcha plugin.
*
* @param string $id The id of the field.
*
* @return boolean True on success
*
* @since 2.5
* @throws \RuntimeException
*/
public function initialise($id)
{
$arg = ['id' => $id];
$this->update('onInit', $arg);
return true;
}