return getProperties().remove(key);
    }

    @Override
    public void save(final OutputStream out, final String comments) {
        throw new UnsupportedOperationException("Unsupported operation.");
    }

    @Override
    public Object setProperty(final String key, final String value) {
        return getProperties().setProperty(key, value);
    }

    @Override
    public int size() {