anchor.diff:  :: /norestart [no restart]
   :: /NoRefresh [no refresh]
   :: /InstallSelectableItems NativeLanguageSupport_Group [select Visual C++ for installing]
  -start /wait visual_installer.exe /passive /norestart /NoRefresh /InstallSelectableItems NativeLanguageSupport_Group
  +start /wait vs_installer.exe /passive /norestart /NoRefresh /InstallSelectableItems NativeLanguageSupport_Group
   if %errorlevel% == 0 (
     echo Install Visual Studio 2015 success!
   ) else (
  
positive.code: :: ===== start step 6: java jre =====
  :java-jre
  echo ">>>>>>>> step [6/7]: java jre"
  java > nul 2> nul || call :install_java
  goto xly-agent
  
  :install_java
  
negative.code: :: ===== start step 5: CUDA 10 =====
  :cuda10
  echo ">>>>>>>> step [5/7]: CUDA 10.2"
  cmd /C nvcc --version 2> nul | findstr /C:"10.2" > nul 2> nul || call :install_cuda
  goto java-jre
  
  :install_cuda
  