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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 deleteLabel(self, label_id):
 """Deletes a label. Args: label_id (str):
 Label id. """

        if label_id not in self._labels:
            return

        label = self._labels[label_id]
        label.delete()
        for node in self.all():
            node.labels.remove(label)