=begin
= RUNIT::Teardownable module

== Methods:

: attach_teardown(teardownmethod, testmethod1 [,testmethod2,...])
      Attaches ((|teardownmethod|)) to ((|testmethod1|)) (, ((|testmethod2|))).
      The ((|teardownmethod|)) is called after ((|testmethod1|)) (, ((|testmethod2|))) called,
      before ((|teardown|)) called

: invoke_teardown(testmethod1)
      Invokes teardown method which is attached to ((|testmethod1|)). 
      If the teardown not found, then does nothing.

=end
