presto-main/src/main/java/io/prestosql/operator/WorkProcessorOperatorAdapter.java/ProcessorContext/ProcessorContext
class ProcessorContext:        public ProcessorContext(Session session, MemoryTrackingContext memoryTrackingContext, OperatorContext operatorContext)
        {
            this.session = requireNonNull(session, "session is null");
            this.memoryTrackingContext = requireNonNull(memoryTrackingContext, "memoryTrackingContext is null");
            requireNonNull(operatorContext, "operatorContext is null");
            this.driverYieldSignal = operatorContext.getDriverContext().getYieldSignal();
            this.lifespan = operatorContext.getDriverContext().getLifespan();
            this.spillContext = operatorContext.getSpillContext();
        }