FixedMap - interface for Map constraints
FixedMap - fixed set of keys
optimized for small fixed set of keys
guarantees all keys are present
can guarantee non null return - if V is defined as non nullable
EnumMap
A Map with the additional constraint that Keys are a fixed set, via Enum.
creation implements FixedMap/IndexMap constraints
factory constructors build IndexMap by default
wrap String handling via .name around IndexMap.
Adds Serialization using Enum.name to a Map,
Keys inherit from Enum -
index via Enum.index -> create a parallel array map by default
String name via Enum.name -> directly use for serialization
Serialization of Map<Enum, V> interface
Methods on loose contraints Map<Enum, V>
Enum.name base methods are applicable regardless of EnumMap FixedMap constraints
add fills existing Map only
