code: def _find_any(self, task_spec):
          
          tasks = []
          if self.task_spec == task_spec:
              tasks.append(self)
          for child in self:
              if child.task_spec != task_spec:
                  continue
              tasks.append(child)
          return tasks
docs: Returns any descendants that have the given task spec assigned.
  
          :type  task_spec: TaskSpec
          :param task_spec: The wanted task spec.
          :rtype:  list(Task)
          :returns: The tasks objects that are attached to the given task spec.