code: def is_supergroup(self, subgroup):
          
          warnings.warn("This is not fully functional. Only trivial subsets are "
                        "tested right now. ")
          return set(subgroup.symmetry_ops).issubset(self.symmetry_ops)
docs: True if this group is a supergroup of the supplied group.
  
          Args:
              subgroup (SymmetryGroup): Subgroup to test.
  
          Returns:
              True if this group is a supergroup of the supplied group.