$this to(string $channel) Set the Slack channel the message should be sent

$this content(string $content) Set the content (text) of the attachment

array toArray() Get an array representation of the message.

$this error() Indicate that the notification gives information about an

$this subject(string $subject) Set the subject of the notification.

$this level(string $level) Set the "level" of the notification (success

$this subject(string $subject) Set the subject of the notification.