code: function forEach(parameters, dIt = global.it, dDescribe = global.describe) {
    const it = makeTestCaseDefiner(parameters, dIt);
    it.skip = makeParameterizedSkip(parameters, dIt);
    it.only = makeParameterizedOnly(parameters, dIt);
    const describe = makeTestCaseDefiner(parameters, dDescribe);
    describe.skip = makeParameterizedSkip(parameters, dDescribe);
    describe.only = makeParameterizedOnly(parameters, dDescribe);
    return { it, describe };
  }
docs: Defines Mocha test cases for each given parameter.
  @param {Array} parameters
  @param {function} dIt - The 'it' function used in this function.
  If omitted, 'it' in global name space is used.
  @param {function} dDescribe - The 'describe' function used in this function.
  If omitted, 'describe' in global name space is used.
  @return {Object} The object which has a method to define test cases.