/// <summary>
        /// Handles when a key is raised on a map.
        /// </summary>
        /// <param name="sender">The <see cref="IToolTargetMapContainer"/> the event came from. Cannot be null.</param>
        /// <param name="map">The <see cref="EditorMap"/>. Cannot be null.</param>
        /// <param name="camera">The <see cref="ICamera2D"/>. Cannot be null.</param>
        /// <param name="e">The <see cref="System.Windows.Forms.MouseEventArgs"/> instance containing the event data. Cannot be null.</param>
        protected override void MapContainer_KeyUp(IToolTargetMapContainer sender, EditorMap map, ICamera2D camera, KeyEventArgs e)
        {
            // Handle deletes
            if (e.KeyCode == Keys.Delete)
            {
                // Only delete when it is an Entity that is on this map
                var removed = new List <object>();
                foreach (var x in SOM.SelectedObjects.OfType <MapGrh>().ToImmutable())
                {
                    if (map.Spatial.CollectionContains(x))
                    {
                        map.RemoveMapGrh(x);
                        removed.Add(x);
                    }
                }

                SOM.SetManySelected(SOM.SelectedObjects.Except(removed).ToImmutable());
            }

            base.MapContainer_KeyUp(sender, map, camera, e);
        }