public static List <UEdge2i> ConnectedCells_ExpansionEdges_List( this PM_Maze maze ) { List <UEdge2i> expansionEdges = new List <UEdge2i>(); List <Vec2i> connectedCells = maze.ConnectedCells_List(); foreach (var cell in connectedCells) { if (maze.Q_Is_Cell_Connected(cell)) { expansionEdges.AddRange(maze.Cell_ExpansionEdges_List(cell)); } } return(expansionEdges); }