A class for building and working with messages grouped by keys.
Return all messages in a flat array.
Returns true if any messages are found.
Get the total number of messages.
Dehydrate this class' state and get it.
Returns the first message.
Returns true if the given group has the message.
All group keys of messages.
Add a message to a group.
Rehydrate a state into this class.
Flat array of only distinct messages.