How does recovery sytem works in Silk Test?

Please explain with code?Explain reraise function.What is the extension of the file in Silk where we store declarations?

SilkTest maximizes your productivity by providing a completely integrated recovery system, which makes it possible for you to run your tests unattended. When the application you are testing fails, or even crashes, the
recovery system restores the application to its base state so that the rest of
your tests can continue to run.

The recovery system can restore your application to its base state at any point during testcase execution:

Before the first line of your testcase begins running, the recovery system restores the application to the base state even if an unexpected event corrupted the application between testcases.

During a testcase, if an application error occurs, the recovery system terminates the execution of the testcase, writes a message in the error log, and restores the application to the base state before running the next testcase.

After the testcase completes, if the testcase was not able to clean up after itself (for example, it could not close a dialog it opened), the recovery system restores the application to the base state.