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

def add_flex_arithmetic_methods(cls):
    """
    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
    """
    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)