anchor.diff:      var result;
       try {
         result = Function.apply(options['method'], args);
  -      if (result != expected) {
  +      if (((expected - result).abs() > DELTA)) {
           throw new Exception('$f($args) failed but should have passed');
         }
       } on StatisticsException {
  
positive.code: library statistics_test;
  
  import 'package:statistics/statistics.dart';
  
  
  void test(Map options) {
  
negative.code:     'args':[],
      'expect': {
        []: 'StatisticsException',
        [1, 2, 3]: 2,
        [1.0, 1.5, 1.6]: 1.366666,
        [1.0, -1.0, 2.0, -2.0]: 0
      }
    });
  }
  
  void main() {
    testMean();
  
    print('-------------------------------------');
    print('All tests complete.');
    print('-------------------------------------');
  }
  