public void record(@Nonnull String context) throws IllegalArgumentException {
  checkNotNull(context);
  if (!store.add(context)) {
    throw new IllegalArgumentException("Context is already claimed: " + context);
  }
}

public void record ( @ Nonnull String context ) throws IllegalArgumentException { checkNotNull ( context ) ; if ( ! store . add ( context ) ) { throw new IllegalArgumentException ( "Context is already claimed: " + context ) ; } }
records the given context .
