def forward(self, step):
x = self.pos_x + math.cos(math.radians(self.rotation)) * step<EOL>y = self.pos_y + math.sin(math.radians(self.rotation)) * step<EOL>prev_brush_state = self.brush_on<EOL>self.brush_on = True<EOL>self.move(x, y)<EOL>self.brush_on = prev_brush_state<EOL>
Move the turtle forward.

        :param step: Integer. Distance to move forward.