Use wrappers from golang.org/x/sys/windows
Use wrappers from golang.org/x/sys/windows

Use the FileLockEx and UnlockFileEx wrappers and the corresponding
LOCKFILE_* and the ERROR_LOCK_VIOLATION error constants from the
golang.org/x/sys/windows package rather than duplicating them in this
package.

alexflint/go-filemutex