CLEVELAND (AP) — A bellwether trial is set to start Monday in federal court in Cleveland to determine whether retail pharmacy chains are liable for costs related to the opioid crisis in two Ohio counties. Lake and Trumbull counties have sued CVS, Walgreens, Walmart and Giant Eagle, claiming the companies created an expensive “public nuisance” by dispensing millions of painkillers into their communities. The companies say they are blameless and that pharmacists merely filled prescriptions written by physicians for legitimate medical needs. The trial could set the tone for similar lawsuits against retail pharmacy chains by government entities across the U.S.