message: Test GasInfo::with_cost and GasInfo::with_externally_used
diff: @@ -99,6 +99,20 @@ impl From<FromUtf8Error> for FfiError {
  mod test {
  use super::*;
  + #[test]
  + fn gas_info_with_cost_works() {
  + let gas_info = GasInfo::with_cost(21);
  + assert_eq!(gas_info.cost, 21);
  + assert_eq!(gas_info.externally_used, 0);
  + }
  +
  + #[test]
  + fn gas_info_with_externally_used_works() {
  + let gas_info = GasInfo::with_externally_used(65);
  + assert_eq!(gas_info.cost, 0);
  + assert_eq!(gas_info.externally_used, 65);
  + }
  +
  // constructors
  #[test]
  