According to https://golang.org/pkg/encoding/json/#Unmarshal

Unmarshal matches incoming object keys to the keys used by Marshal (either the struct field name or its tag), preferring an exact match but also accepting a case-insensitive match

However, if we change to easyjson, it seems we need to be case sensitive, otherwise it fails to unmarshall, in our case, we want to make it can insensitive since our upstream may send both capital or lower case, can we do so in easy json?