def METHOD_NAME(self):
    """Initialize some filesystems with valid and invalid labels."""
    # Ext2FS has a maximum length of 16
    self.assertFalse(fs.Ext2FS().label_format_ok("root___filesystem"))
    self.assertTrue(fs.Ext2FS().label_format_ok("root__filesystem"))
    # FATFS has a maximum length of 11
    self.assertFalse(fs.FATFS().label_format_ok("rtfilesystem"))
    self.assertTrue(fs.FATFS().label_format_ok("rfilesystem"))
    # JFS has a maximum length of 16
    self.assertFalse(fs.JFS().label_format_ok("root___filesystem"))
    self.assertTrue(fs.JFS().label_format_ok("root__filesystem"))
    # ReiserFS has a maximum length of 16
    self.assertFalse(fs.ReiserFS().label_format_ok("root___filesystem"))
    self.assertTrue(fs.ReiserFS().label_format_ok("root__filesystem"))
    # XFS has a maximum length 12 and does not allow spaces
    self.assertFalse(fs.XFS().label_format_ok("root_filesyst"))
    self.assertFalse(fs.XFS().label_format_ok("root file"))
    self.assertTrue(fs.XFS().label_format_ok("root_filesys"))
    # HFS has a maximum length of 27, minimum length of 1, and does not allow colons
    self.assertFalse(fs.HFS().label_format_ok("n" * 28))
    self.assertFalse(fs.HFS().label_format_ok("root:file"))
    self.assertFalse(fs.HFS().label_format_ok(""))
    self.assertTrue(fs.HFS().label_format_ok("n" * 27))
    # HFSPlus has a maximum length of 128, minimum length of 1, and does not allow colons
    self.assertFalse(fs.HFSPlus().label_format_ok("n" * 129))
    self.assertFalse(fs.HFSPlus().label_format_ok("root:file"))
    self.assertFalse(fs.HFSPlus().label_format_ok(""))
    self.assertTrue(fs.HFSPlus().label_format_ok("n" * 128))
    # NTFS has a maximum length of 128
    self.assertFalse(fs.NTFS().label_format_ok("n" * 129))
    self.assertTrue(fs.NTFS().label_format_ok("n" * 128))
    # all devices are permitted to be passed a label argument of None
    # some will ignore it completely
    for _k, v in device_formats.items():
        self.assertIsNotNone(v(label=None))