private void validateRowKey(ResolvedSchema resolvedSchema) {
        Optional<Column> column = resolvedSchema.getColumn(0);
        checkState(column.get().getDataType().getConversionClass() == String.class,
                "The rowKey (first element) must be String");
    }
The base class of {@link RedisSchema}

@param <T> The type of Flink state.
inlong-sort/sort-flink/sort-flink-v1.13/sort-connectors/redis/src/main/java/org/apache/inlong/sort/redis/common/schema/impl/AbstractRedisSchema.java