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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 solid_angles(self, permutation=None):
 """ Returns the list of "perfect" solid angles Each edge is given as a list of its end vertices coordinates. """

        if permutation is None:
            return self._solid_angles
        else:
            return [self._solid_angles[ii] for ii in permutation]