System and methods are provided to cache encoded graphical objects that may be subsequently combined with other encoded video data to form a data stream decodable by a client device according to a format specification. In this steam generator, water provided from a water tank is heated by a heater to generate a steam in a chamber, and then the steam is sprayed out through a steam channel. The one and other write wiring traces constitute a signal line pair, the second and fifth lines are arranged on an upper surface of the cover insulating layer, and the third and sixth lines are arranged on an upper surface of the base insulating layer. Each component group securing each side of the bracket portions together is configured to closely balance the weight of one lubricator in a partially depleted state, in order to avoid any undue balance problems on the shaft.