code: public static synchronized IStorage openStorage(final File pFile) throws TTException {
          checkState(existsStorage(pFile), "DB could not be opened (since it was not created?) at location %s",
              pFile);
          StorageConfiguration config = StorageConfiguration.deserialize(pFile);
          final Storage storage = new Storage(config);
          final IStorage returnVal = STORAGEMAP.putIfAbsent(pFile, storage);
          if (returnVal == null) {
              return storage;
          } else {
              return returnVal;
          }
      }
docs: Open database. A database can be opened only once. Afterwards the
  singleton instance bound to the File is given back.
  
  @param pFile
  where the database is located sessionConf a {@link SessionConfiguration} object to set up
  the session
  @return {@link IStorage} instance.
  @throws TTException
  if something odd happens