balanceOfToken method
Implementation
Future<BigInt> balanceOfToken(
String caller, String tokenContractAddress) async {
Contract contract = Contract.fromJsonString(vthoAbi);
var map = await call(
caller, contract, 'balanceOf', [caller], tokenContractAddress);
String b = map['data'];
BigInt balance = BigInt.parse(b.substring(2), radix: 16);
return balance;
}