def test_iadd(self, evt):
        rval = event.ReturnValue(append_events=[evt])
        rval2 = event.ReturnValue(eat=True, append_events=[evt])
        rset = event.ResultSet()

        rset += rval
        rset += rval2
        rset += None
        assert rset.eat
        assert rset.append_events == [evt, evt]
def line(self, x, y, length, horizontal):
		if horizontal:
			self.board[y,x:x+length] = self.color
		else:
			self.board[y:y+length,x] = self.color