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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 fail(self):
 """ Fail a node, setting its status to "failed". Also fails all vectors that connect to or from the node. You cannot fail a node that has already failed, but you can fail a dead node. Set node.failed to True and :attr:`~dallinger.models.Node.time_of_death` to now. Instruct all not-failed vectors connected to this node, infos made by this node, transmissions to or from this node and transformations made by this node to fail. """

        if self.failed is True:
            raise AttributeError("Cannot fail {} - it has already failed.".format(self))
        else:
            self.failed = True
            self.time_of_death = timenow()
            self.network.calculate_full()

            for v in self.vectors():
                v.fail()
            for i in self.infos():
                i.fail()
            for t in self.transmissions(direction="all"):
                t.fail()
            for t in self.transformations():
                t.fail()