* provide 'automatic' token URI by appending the token ID to the base URI, if a base is set but no token-specific URI is available * make the three cases more explicit, avoid else after return * adjust comments to reflect reality
* provide 'automatic' token URI by appending the token ID to the base URI, if a base is set but no token-specific URI is available * make the three cases more explicit, avoid else after return * adjust comments to reflect reality