OffChainMetadata constructor
      const
      OffChainMetadata({ 
    
    
- required String name,
- required String description,
- required String symbol,
- required String image,
- required Properties? properties,
- required List<Attribute> attributes,
- required Collection? collection,
Implementation
const OffChainMetadata({
  required this.name,
  required this.description,
  required this.symbol,
  required this.image,
  required this.properties,
  required this.attributes,
  required this.collection,
});