class Key implements IKey {

    @Override
    public boolean equals(final Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        Key key = (Key) o;

        return !(identifier != null ? !identifier.equals(key.identifier) : key.identifier != null);

    }

    public  Key(final String identifier);

}