message: add properties on object
diff: @@ -18,10 +18,9 @@ export class NetworkError extends Error implements INetworkError {
  super(errorMessage);
  customProperties.push([INetworkErrorProperties.online, online]);
  for (const [key, val] of customProperties) {
  - Object.defineProperty(NetworkError.prototype, key, {
  - get: () => {
  - return val;
  - },
  + Object.defineProperty(this, key, {
  + value: val,
  + writable: false,
  });
  this.customProperties.set(key, val);
  }
  