EnumItem
@Js
const mixin EnumItem : Item
EnumItem is one key of an EnumItems. It is an Item so its
display text, icon, color, and meta work anywhere items are
rendered.
Documentation for this key or null
The enumerated key
abstract Str? doc()
Documentation for this key or null. Never inherited: an item without its own doc reports null rather than its enum type's.
abstract Str key()
The enumerated key. This is the value stored in a record, and
may contain arbitrary characters when mapping to an external
enumeration - use this, not id, as the value.