Test = function (name, f) {
    if (!f) throw new Error('Undefined test function');
    if (!/function[^\(]*\(([^,\)]*)/.test(f.toString())) {
      throw new Error('"' + name + '" test: Test is not a valid Function object');
    }
    this.loopArg = RegExp.$1;
    this.name = name;
    this.f = f;
  }
Test manages a single test (created with
JSLitmus.test())

@private