def move(self, source, dest):
        """
        the semantic should be like unix 'mv' command.
        Unfortunatelly, shutil.move does work differently!!!
        Consider (all paths point to directories)
        mv /a/b /a/c
        expected outcome:
        case 1.: 'c' does not exist:
          b moved over to /a such that /a/c is what was /a/b/ before
        case 2.: 'c' does exist:
          b is moved into '/a/c/' such that we have now '/a/c/b'

        But shutil.move will use os.rename whenever possible which means that
        '/a/b' is renamed to '/a/c'. The outcome is that the content from b
        ends up in c.
        """
        if dest.scheme == 'file':
            if source.isdir() and dest.isdir():
                dest /= source.basename()
            return shutil.move(source.path, dest.path)
        else:
            return super(LocalFileSystem, self).move(source, dest)