@Override
        public String toString() {
            return "TimestampAndOffset(" +
                    "timestamp=" + timestamp +
                    ", offset=" + offset +
                    ", leaderEpoch=" + leaderEpoch +
                    ')';
        }
Open a channel for the given file
For windows NTFS and some old LINUX file system, set preallocate to true and initFileSize
with one value (for example 512 * 1025 *1024 ) can improve the kafka produce performance.
@param file File path
@param mutable mutable
@param fileAlreadyExists File already exists or not
@param initFileSize The size used for pre allocate file, for example 512 * 1025 *1024
@param preallocate Pre-allocate file or not, gotten from configuration.
clients/src/main/java/org/apache/kafka/common/record/FileRecords.java