public async Task<MutantTestResults> RunTests()
        {
            string name = string.Format("muttest-{0}.xml", Path.GetFileName(_assemblyPath));
            string outputFilePath = new FilePathAbsolute(_assemblyPath).GetBrotherFileWithName(name).ToString();

            if (_testsSelector.IsEmpty)
            {
                _testResults = new MutantTestResults();
                return TestResults;
            }
            _testResults = await RunTests(_assemblyPath,
                outputFilePath);
            return TestResults;
        }
        public async Task <MutantTestResults> RunTests()
        {
            string name           = string.Format("muttest-{0}.xml", Path.GetFileName(_assemblyPath));
            string outputFilePath = new FilePathAbsolute(_assemblyPath).GetBrotherFileWithName(name).ToString();

            if (_testsSelector.IsEmpty)
            {
                _testResults = new MutantTestResults();
                return(TestResults);
            }
            _testResults = await RunTests(_assemblyPath,
                                          outputFilePath);

            return(TestResults);
        }