code: public synchronized void unregister(final OStorage iStorage) {
  		for (ODatabaseComplex<?> db : new HashSet<ODatabaseComplex<?>>(instances.keySet())) {
  			if (db != null && db.getStorage() == iStorage) {
  				db.close();
  				instances.remove(db);
  			}
  		}
  	}
docs: Unregisters all the database instances that share the storage received as argument.
  
  @param iStorage