flushSync method
Synchronously flushes the contents of the file to disk.
Throws a FileSystemException if the operation fails.
Implementation
void flushSync();© 2012 the Dart project authors
Licensed under the BSD 3-Clause "New" or "Revised" License.
https://api.dart.dev/stable/2.18.5/dart-io/RandomAccessFile/flushSync.html