code: public static StorageException generateNewUnexpectedStorageException(final Exception cause) {
          final StorageException exceptionRef = new StorageException(StorageErrorCode.NONE.toString(),
                  "Unexpected internal storage client error.", 306, // unused
                  null, null);
          exceptionRef.initCause(cause);
          return exceptionRef;
      }
docs: Returns an unexpected storage exception.
  
  @param cause
  An <code>Exception</code> object that represents the initial exception that caused the unexpected
  error.
  
  @return A {@link StorageException} object that represents the unexpected storage exception being thrown.