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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def action(name, factory, label=None, desc=None):
 """ Annotate a model's action. @param name: the name of the model's action. @type name: str or unicode @param factory: a factory to create actions. @type factory: IActionFactory @param label: the action label if specified. @type label: str or unicode or None @param desc: the action description if specified. @type desc: str or unicode or None """

    _annotate("action", name, factory,
              label=label, desc=desc)