flink table primary key与format 关联

flink table primary key与format 有一定关联性，不是所有format都可以支持PK.
如出现如下错误：
Caused by: org.apache.flink.table.api.ValidationException: The Kafka table ‘default_catalog.default_database.KafkaVersionTable’ with ‘csv’ format doesn’t support defining PRIMARY KEY constraint on the table, because it can’t guarantee the semantic of primary key.

即代表format是不支持的，关键代码如下：

 private static void validatePKConstraints(
            ObjectIdentifier tableName, CatalogTable catalogTable, Format format)