Instead of providing this blanket property for all DataCenters, I would rather have this be specific to a <code>DataCenterInfo</code> and <code>AmazonInfo</code> specific logic in <code>PeerAwareInstanceRegistry</code> move to <code>AmazonInfo</code>. 
Now, since <code>DataCenterInfo</code> is public we would have to either provide a new interface for this specific behavior (not ideal) or have a new <code>DataCenterInfo</code> interface, extending the existing interface and add this functionality. In <code>PeerAwareInstanceRegistry</code> we check if the <code>DataCenterInfo</code> implements this new interface, if yes, delegate else return false.