question: @ Override public ShapeTileSimplex to_Simplex ( ) { if ( is_empty ( ) ) return ShapeTileSimplex . EMPTY ; ArrayList < PlaLineInt > line_arr = new ArrayList < PlaLineInt > ( 4 ) ; line_arr . add ( new PlaLineInt ( box_ll , PlaDirection . RIGHT ) ) ; line_arr . add ( new PlaLineInt ( box_ur , PlaDirection . UP ) ) ; line_arr . add ( new PlaLineInt ( box_ur , PlaDirection . LEFT ) ) ; line_arr . add ( new PlaLineInt ( box_ll , PlaDirection . DOWN ) ) ; return new ShapeTileSimplex ( line_arr ) ; }
target:  Returns an object of class Simplex defining the same shape