Dart Functions

functiontest.dart

class FunctionTest {
 FunctionTest(this.myFunc);
 Function myFunc;
 num run(num n) {
  return myFunc(n);
 }
}
main() {
 var square = (aNumber) => aNumber * aNumber;
 var result = new FunctionTest(square).run(5);
 var squareRoot = (aNumber) { 
                      print(aNumber); 
                      return Math.sqrt(aNumber);
                  };
 print(new FunctionTest(squareRoot).run(result));
}