`_. * @param string $value Fire the trigger when usage crosses this value. * @param string $url The URL to request when the trigger fires. * @param array $params Optional parameters for this trigger. A full list of parameters can be found in the `Usage Trigger documentation `_. * @return Services_Twilio_Rest_UsageTrigger The created trigger */ function create($category, $value, $url, array $params = array()) { return parent::_create(array( 'UsageCategory' => $category, 'TriggerValue' => $value, 'CallbackUrl' => $url, ) + $params); } }