In a drug-pricing case with potentially “huge” damage awards, a federal judge has approved the use of a random-sampling process for document discovery.U.S. Magistrate Judge Iain D. Johnston this week ruled the plaintiffs’ proposal to double-check a statistically random sample of documents for relevant information is reasonable under the Federal Rules of Civil Procedure.In a nine-page decision on Tuesday, Johnston wrote such a method was preferable over the defendants’ idea — basically, to hold …