Debugging processes
Testing processes often requires finding errors and removing them, which is called debugging.
Usually, a process is a black box. You can see that it runs and completes successfully or with an error. If a process fails, you cannot see the values of variables or a function's return value, which might have caused the error. Thus, one basic debugging tactic is to output such values when the process is running. The Application Engine contains some functions that allow to output such information during the debug phase.