code: def forward(self, step):
          
          x = self.pos_x + math.cos(math.radians(self.rotation)) * step
          y = self.pos_y + math.sin(math.radians(self.rotation)) * step
          prev_brush_state = self.brush_on
          self.brush_on = True
          self.move(x, y)
          self.brush_on = prev_brush_state
docs: Move the turtle forward.
  
          :param step: Integer. Distance to move forward.