usecrate::VectorGrid;/// Air tiles are tiles that the grid sees as unimportant filler space.
/// You can shave off air tiles by calling VectorGrid.trim()
////// For this to work, it is importand that every tile returned by the default is also an air tile.
pubtraitAir: Default {/// Returns true if this tile is an air tile.
/// Air tiles are tiles that the grid sees as unimportant filler space.
fnis_air(&self)->bool;}impl<ItemType: Air>VectorGrid<ItemType>{}