Please answer the following question: Question: "What intangible object is central to the proper functioning of a lighting fixture?" Context: "Lighting fixtures come in a wide variety of styles for various functions. The most important functions are as a holder for the light source, to provide directed light and to avoid visual glare. Some are very plain and functional, while some are pieces of art in themselves. Nearly any material can be used, so long as it can tolerate the excess heat and is in keeping with safety codes." Answer:
A:
safety codes