runGuarded abstract method 
  R runGuarded<R>(Executes the given action in this zone and catches synchronous errors.
This function is equivalent to:
try {
  return this.run(action);
} catch (e, s) {
  return this.handleUncaughtError(e, s);
}
 See run.
Source
R runGuarded<R>(R action());
    © 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
    https://api.dartlang.org/stable/1.24.3/dart-async/Zone/runGuarded.html