Gets the top-level directory for the test run that contains deployed files and result files.
Assembly: Microsoft.VisualStudio.QualityTools.UnitTestFramework (in Microsoft.VisualStudio.QualityTools.UnitTestFramework.dll)
This value is the path to the directory that is created to contain the deployment directory. This is used to organize test runs. Each test run will be identified by the path to the TestDir.