code: def do_set(self, arg):
          
          if arg in self.tests:
              self.active = arg
              #Create a default argument set and analysis group for the current plotting
              if arg not in self.args:
                  self.args[arg] = {"default": dict(self._template_args)}
                  self.group = "default"
              else:
                  self.group = list(self.curargs.keys())[0]
                  
              #Change the prompt so that they know which unit test is being edited.
              self._set_def_prompt()
          else:
              msg.err("The test case '{}' is not valid.".format(arg))
docs: Sets the specified 'module.executable' to be the active test result to interact with.