In Go, I would normally have my own time function which would return the std lib time function, which works flawlessly for testing my own code. The problem is i

In Go, I would normally have my own time function which would return the std lib time function, which works flawlessly for testing my own code. The problem is if there is foreign code(ie. 3rd library dependency) that uses time and which makes obviously calls to the std library time, making it untestable. The only solution is to overwrite time on language level by some trickery(not all languages allow this) or literally change the OS's clock and test manually one test at a time. This is one of those unsolved programming issues.