=begin
= RUNIT::RObserver module

== Methods:
: add_error(at, err)
      You can override this method to do something when error raised.
      The at argument specifies where the error raised.
      The err argument specifies the error information.

: add_failure(at, fail)
      You can override this method to do something when failure raised.
      The at argument specifies where the AssertionFailedError raised.
      The fail argument specifies the AssetionFailedError information.

: end_test(test)
      You can overrided this method to do something
      when finishing each test case.
      The ((|test|)) argument specifies the test case.

: start_test(test)
      You can overrided this method to do something
      when starting each test case.
      The ((|test|)) argument specifies the test case.
=end

