Spark广播自定义BiMap类的序列化

Trying to make a Spark broadcast BiMap that is composed of two Maps. Since the mappings are unique from either direction all that should be serialized is a single Map, actually only the a Seq[(K, V)] needs to be serialized. So the underlying forward Map's elements only. In the deserialization we can recreate the inverse Map and indexes.Trying to make a Spark broadcast BiMap that is