estimateGas method
Implementation
Future<BigInt> estimateGas(String method,
[List<dynamic> args = const []]) async {
final iface = Interface(abi);
final encode = iface.encodeFunctionData(method, args);
return BigInt.from(await promiseToFuture(_estimateGas(RequestEstimateGas(
from: signer,
to: address,
data: encode,
))));
}