Resolved error typing. Needs to adapt to Content::Map with non-String keys.
Resolved error typing. Needs to adapt to Content::Map with non-String keys.

`EnumDeserializer` is being adapted from:
  `serde_json::Value::Map<Vec<(String, Value)>>`
serde has a Map variant that allows non-String keys:
  `serde::de::Content::Map<Vec<(Content, Content)>>`

There's a lot of assumptions in `EnumDeserializer` about `String` keys and I'm not sure what the adaptation should be.

serde-rs/serde