presto-main/src/main/java/io/prestosql/operator/OperatorContext.java/OperatorContext/newLocalSystemMemoryContext
class OperatorContext:    public LocalMemoryContext newLocalSystemMemoryContext(String allocationTag)
    {
        return new InternalLocalMemoryContext(operatorMemoryContext.newSystemMemoryContext(allocationTag), memoryFuture, this::updatePeakMemoryReservations, true);
    }