tags.removeAll() doesn't work

in illustrator scripting tags.removeAll() doesn’t seem to do anything

example:

selection[0].tags.add()

alert(selection[0].tags.lengh) // result = 1

selection[0].tags.removeAll() // no errors

alert(selection[0].tags.lengh) // result = 1

// but remove individual tag works

selection[0].tags[0].remove()

alert(selection[0].tags.lengh) // result = 0

what give? I can loop and remove all tags that way but that’s not fun.