message: Rename `visible_in` to `within` in `game_of_life`
diff: @@ -339,7 +339,7 @@ mod grid {
  let region = self.visible_region(frame.size());
  - for cell in self.life.visible_in(region) {
  + for cell in self.life.within(region) {
  frame.fill_rectangle(
  Point::new(cell.j as f32, cell.i as f32),
  Size::UNIT,
  @@ -433,7 +433,7 @@ mod grid {
  self.cells.insert(cell);
  }
  - fn visible_in(&self, region: Rectangle) -> impl Iterator<Item = &Cell> {
  + fn within(&self, region: Rectangle) -> impl Iterator<Item = &Cell> {
  let first_row = (region.y / Cell::SIZE as f32).floor() as isize;
  let first_column = (region.x / Cell::SIZE as f32).floor() as isize;
  