}
		d.copyWithChildren(src, dataUsageHash(ch), &hash)
	}
	if parent != nil {
		p := d.Cache[parent.Key()]
		p.addChild(hash)
		d.Cache[parent.Key()] = p
	}
}

// reduceChildrenOf will reduce the recursive number of children to the limit
// by compacting the children with the least number of objects.
func (d *dataUsageCache) reduceChildrenOf(path dataUsageHash, limit int, compactSelf bool) {