presto-memory-context/src/main/java/io/prestosql/memory/context/MemoryTrackingContext.java/MemoryTrackingContext/initializeLocalMemoryContexts
class MemoryTrackingContext:    public void initializeLocalMemoryContexts(String allocationTag)
    {
        this.userLocalMemoryContext = userAggregateMemoryContext.newLocalMemoryContext(allocationTag);
        this.revocableLocalMemoryContext = revocableAggregateMemoryContext.newLocalMemoryContext(allocationTag);
        this.systemLocalMemoryContext = systemAggregateMemoryContext.newLocalMemoryContext(allocationTag);
    }