def METHOD_NAME(fd):
    # https://lists.apple.com/archives/darwin-dev/2005/Feb/msg00072.html
    # https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man2/fsync.2.html
    # https://github.com/untitaker/python-atomicwrites/issues/6
    fcntl.fcntl(fd, fcntl.F_FULLFSYNC)