I think the following case shoul...

I think the following case should be valid: the direction of flight is beyond the wall (let's say its a strong bullet).

For example:

assert checkio([[0, 1], [1, 2], [2, 0], [-2, 4]]) == True, "Strong Bullet"

I'm not sure if it is a valid case, but there is no evidence why it couldn't happen.

What do you think?