Downloads testlib.h from the official GitHub repository.
Saves the file to the current working directory and provides
platform-specific installation instructions for system-wide usage.
Returns Promise<void>
Resolves when download and save complete
Throws
If download from GitHub fails
Throws
If file write fails
Example
// From CLI: polyman download-testlib awaitdownloadTestlibAction(); // Downloads testlib.h to current directory // Shows installation instructions for /usr/include or /usr/local/include
Downloads testlib.h from the official GitHub repository. Saves the file to the current working directory and provides platform-specific installation instructions for system-wide usage.