Traverse traverses the given breadcrumber recursively.

TryBreadcrumb accepts a nilable breadcrumber and handles it appropriately.

TrySetUnread tries to check if a breadcrumber parent node supports Unreadabler.

Unreadable is a struct that nodes could embed to implement unreadable capability, that is, the unread and mentioned states.

UnreadableState implements a map of unread children for indication.

Breadcrumber is the base interface that other interfaces extend on.

Unreadabler extends Breadcrumber to add unread states to the parent node.

UnreadSetter is an interface that a single row implements to set state.