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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 get_crumbs(self):
 """ Get crumbs for navigation links. Returns: tuple: concatenated list of crumbs using these crumbs and the crumbs of the parent classes through ``__mro__``. """

        crumbs = []
        for cls in reversed(type(self).__mro__[1:]):
            crumbs.extend(getattr(cls, 'crumbs', ()))
        crumbs.extend(list(self.crumbs))
        return tuple(crumbs)