return value;
    public ParameterValue unmarshal(final ParameterStore store) {        final ParameterValue value = new ParameterValue();        final String literal = store.read(this);        if (literal != null) {            if (m_entries.containsKey(literal)) {                value.setValue(m_entries.get(literal));            } else {                value.addError("It must be one of the following: " +                               m_entries.keySet());            }        }        return value;    }