Assignment 8

Again, here you're changing the position which we don't exactly want to do. Really, all this particular function does is test if the position being passed is legal for this piece and returns true or false. If you change `self.position` you're defeating the purpose of testing whether or not the move itself  should be allowed before it happens. This function is like a customs officer; it checks that you're allowed to be in the country before you're legally in the country.