OptionalisWhether the field is optional (not in required).
OptionalisWhether the field is nullable (anyOf [T, null] or type: ["...", "null"]).
OptionaldefaultDefault value from the schema's default keyword.
OptionalexamplesExample values from the schema's examples keyword.
Key name validation schema (from propertyNames).
Value schema (from additionalProperties).
Properties common to every WalkedField variant. The
typefield acts as the discriminant for the tagged union.