Chapter0 of eola class NumericVsGeometric green line in the scene doesn't go away.

it looks like this but ideally there is no green line here because the transformation
`Transform(self.vline, new_line)`
and
`Transform(self.hline, new_line)`

By making some change of the code it seems that `setup` function was called twice thereby create two vlines and two hlines. But still, I have no idea why this happens.