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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 unlabel_rigid_bodies(self):
 """Remove all rigid body labels from the Compound """

        self._check_if_contains_rigid_bodies = True
        for child in self.children:
            child._check_if_contains_rigid_bodies = True
        for particle in self.particles():
            particle.rigid_id = None