presto-main/src/main/java/io/prestosql/operator/aggregation/AbstractGroupCollectionAggregationState.java/AbstractGroupCollectionAggregationState/ensureCapacity
class AbstractGroupCollectionAggregationState:    @Override
    public void ensureCapacity(long size)
    {
        headBlockIndex.ensureCapacity(size);
        headPosition.ensureCapacity(size);
        tailBlockIndex.ensureCapacity(size);
        tailPosition.ensureCapacity(size);
        groupEntryCount.ensureCapacity(size);
    }