function visit(obj, file) {
    var suite;
    for (var key in obj) {
      if (typeof obj[key] === 'function') {
        var fn = obj[key];
        switch (key) {
          case 'before':
            suites[0].beforeAll(fn);
            break;
          case 'after':
            suites[0].afterAll(fn);
            break;
          case 'beforeEach':
            suites[0].beforeEach(fn);
            break;
          case 'afterEach':
            suites[0].afterEach(fn);
            break;
          default:
            var test = new Test(key, fn);
            test.file = file;
            suites[0].addTest(test);
        }
      } else {
        suite = Suite.create(suites[0], key);
        suites.unshift(suite);
        visit(obj[key], file);
        suites.shift();
      }
    }
  }
TDD-style interface:

    exports.Array = {
      '#indexOf()': {
        'should return -1 when the value is not present': function() {

        },

        'should return the correct index when the value is present': function() {

        }
      }
    };

@param {Suite} suite Root suite.