Tzip16Contracts extends the Contract which means it has all the functions you can call on a contract along with that it provides getMetaData and metadataViews method to get meta data of Fa1.2 and fa2 Contract.
A standard for accessing contract metadata in JSON format in on-chain storage or off-chain using IPFS or HTTP(S).
Example of getMetaData:
Tzip16Contract tzip16Contract = Tzip16Contract(
rpcServer: '<https://mainnet.api.tez.ie>',
address: 'KT1StkBRUfJD9AuHAE4oQVi49qLQhsgeDcU1',
);
var metaData = await tzip16Contract.getMetadata();
print(metaData);
Example of metadataView :
Tzip16Contract tzip16Contract = Tzip16Contract(
rpcServer: '<https://mainnet.api.tez.ie>',
address: 'KT1StkBRUfJD9AuHAE4oQVi49qLQhsgeDcU1',
);
var metaView = await tzip16Contract.metadataViews();
print(metaView);