How to catch SIGINT for the current in Dart?

How can Ctrl+C or SIGINT be caught in a Dart program for the current process?

Something similar to this for Node:

process.on('SIGINT', function() {
    // do stuff
});

It looks like the SIGUSR1 and SIGUSR2 fields used in the old answer are now deprecated. I got the following example working using the sigint field:

import "dart:io";

void main() {
  var n = 0;
  ProcessSignal.sigint.watch().listen((signal) {
    print(" caught ${++n} of 3");

    if (n == 3) {
      exit(0);
    }
  });
}