human
I wrote the below code

    from_filesystem = from_volume.get_filesystem()
    to_filesystem = to_volume.get_filesystem()
    getting_snapshots = to_filesystem.snapshots()
    def got_snapshots(snapshots):
        with from_filesystem.reader(snapshots) as reader:
            with to_filesystem.writer() as writer:
                for chunk in iter((lambda : reader.read(4096)), ''):
                    writer.write(chunk)
    getting_snapshots.addCallback(got_snapshots)
    return getting_snapshots

What's a good function header?
 Here's a good function header?
assistant
#Here's a good function header.

def copy(from_volume, to_volume):