operator fun get(version: Int?, identifier: String): ProductInfo?
Returns an entity.
version - latest version of seller, may be null (if latest data needed)
identifier - identifies entity. must match to Constraints.WINDOWS_FILENAME_REGEX
com.srv4pos.server.api.exceptions.VersionConflictJsonException - if version mismatch
com.srv4pos.server.api.exceptions.NotFoundJsonException - if entity is not found
Return
null if not modified since version or entity. if version is null then return value can not be null