Marks a Map property on a bean that unmapped JSON properties go into.
This property is considered transient (not mapped to a DB column) unlike @DbJson but will be
written to JSON output (unless it also annotated with @JsonIgnore).
Being JSON read and written means that in a document store only (ElasticSearch only) case it can hold all top level unmapped properties.
Example:
@UnmappedJson
Map<String, Object> unmapped;