The current plugin's IRCPluginState, via which to send messages to the server.
Channel in which to send the message.
Message body content to send.
Colour of the announcement, one of "primary", "blue", "green", "orange", "purple".
Custom message properties, such as Message.Property.quiet and Message.Property.forced.
String name of the calling function, or something else that gives context.
Sends an announcement to a Twitch channel.
Requires version TwitchSupport, without which it will just pass on to chan.