presto-main/src/main/java/io/prestosql/operator/Driver.java/Driver/setOwner
class Driver:        private synchronized void setOwner()
        {
            checkState(lock.isHeldByCurrentThread(), "Current thread does not hold lock");
            currentOwner = Thread.currentThread();
            // NOTE: We do not use interrupted stack information to know that another
            // thread has attempted to interrupt the driver, and interrupt this new lock
            // owner.  The interrupted stack information is for debugging purposes only.
            // In the case of interruption, the caller should (and does) have a separate
            // state to prevent further processing in the Driver.
        }