def patch_method_in(cls):
    """
    To use:
        from <somewhere> import <someclass>

        @monkey.patch_method(<someclass>)
        def <newmethod>(self, args):
            return <whatever>

    This adds <newmethod> to <someclass>
    """
    def decorator(func):
        setattr(cls, func.__name__, func)
        return func
    return decorator