readerBuilder

A new builder of a reader that may be older than the writer of what it reads, Wow's builder reading an unknown value of a result's status, a hop's stage or a function's kind as UNKNOWN (WowEnums): the client of a peer that was upgraded first, or a node of the minor version before its cluster's. A reader of requests keeps refusing an unknown value: it is newer than its client, and taking a typo for a value would change its meaning.