code: public boolean addDuplicationStorePolicy(String spaceId,
                                               DuplicationStorePolicy dupStore) {
          LinkedHashSet<DuplicationStorePolicy> dupStores =
              spaceDuplicationStorePolicies.get(spaceId);
          if (dupStores == null) {
              dupStores = new LinkedHashSet<>();
              spaceDuplicationStorePolicies.put(spaceId, dupStores);
          }
          return dupStores.add(dupStore);
      }
docs: Adds a DuplicationStorePolicy for the specified space ID.
  
  @param spaceId  the space ID to add the DuplicationStorePolicy for
  @param dupStore the DuplicationStorePolicy
  @return true if added, false otherwise.  False will be returned if the
  Set<DuplicationStorePolicy> for the specified space already contains the
  dupStore.