static <T> RecordExtractor<T, T> identity() {
            return x -> x;
        }
An interface to extract a value from given argument.

@param <F> The type of given argument
@param <T> The type of the return value
inlong-sort/sort-flink/sort-flink-v1.15/sort-connectors/jdbc/src/main/java/org/apache/inlong/sort/jdbc/internal/JdbcOutputFormat.java