docs: def execute(self, env, args):
          """ Removes a task.
  
              `env`
                  Runtime ``Environment`` instance.
              `args`
                  Arguments object from arg parser.
              """
  
          # extract args
          task_name = args.task_name
          force = args.force
  
          if env.task.active and env.task.name == task_name:
              raise errors.ActiveTask
  
          if not env.task.exists(task_name):
              raise errors.TaskNotFound(task_name)
  
          if force:
              env.task.remove(task_name)
  
          else:
              try:
                  while True:
                      prompt = ('Are you sure you want to delete "{0}" (y/n)? '
                                .format(task_name))
                      resp = env.io.prompt(prompt, newline=False).lower()
  
                      if resp in ('y', 'n'):
                          if resp == 'y':
                              env.task.remove(task_name)
                          break
  
              except KeyboardInterrupt:
                  pass