code: def add_flex_arithmetic_methods(cls):
      
      flex_arith_method, flex_comp_method, _, _, _ = _get_method_wrappers(cls)
      new_methods = _create_methods(cls, flex_arith_method,
                                    flex_comp_method, bool_method=None,
                                    special=False)
      new_methods.update(dict(multiply=new_methods['mul'],
                              subtract=new_methods['sub'],
                              divide=new_methods['div']))
      # opt out of bool flex methods for now
      assert not any(kname in new_methods for kname in ('ror_', 'rxor', 'rand_'))
  
      add_methods(cls, new_methods=new_methods)
docs: Adds the full suite of flex arithmetic methods (``pow``, ``mul``, ``add``)
      to the class.
  
      Parameters
      ----------
      cls : class
          flex methods will be defined and pinned to this class