getOwnedVipers() {
  this.isLoading = true;
  cryptoViperContract.methods.ownedVipers().call({
    from: this.account,
  }).then((receipt) => {
    for (let i = 0; i < receipt.length; i += 1) {
      cryptoViperContract.methods.getViperDetails(receipt[i]).call({
        from: this.account,
      }).then((viper) => {
        this.addViperFromReturned(viper);
      }).catch((err) => {
        console.log(err, 'err');
      });
    }
    this.isLoading = false;
  }).catch((err) => {
    console.log(err, 'err');
    this.isLoading = false;
  });
},