A container holding unit includes an abutting portion and an urging device for urging the abutting portion to a circumference of a container to constrain the container. To obtain the netlist text file, an electrical circuit schematic of an electrical circuit is created using a commercially available electrical schematic capture software tool. Aromatherapy spheres are within the hollows that contain aromatherapy materials. The runners of the connectingadjacent carrier tracks move inside the channel of a rail at the same time and the connectingadjacent carrier tracks slide in parallel under the same channel.