Plaintiff was a tenant of defendant's apartment. While the plaintiff opened a glass sliding door to exit the bathtub in his apartment unit, the door shattered, inflicting severe lacerations upon the plaintiff. There was a range of evidence which showed that regular glass was a recognized hazard in the bathroom, and that shatterproof glass was becoming the industry standard for bathtub enclosures. Should evidence of industry custom factor into a negligence analysis? If so, in what capacity and to what extent?