class PropertyValue implements Serializable, Iterable<PropertyValue> {

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (!(o instanceof PropertyValue)) {
            return false;
        }
        PropertyValue dataNode = (PropertyValue) o;
        return Objects.equals(getKey(), dataNode.getKey()) &&
                Objects.equals(value, dataNode.value);
    }

    public  PropertyValue(String key);
    protected  PropertyValue(String key, String value);

}