def get_instance_method(instance, method_name):
    """
    Return the method_name function for instance.  
    :param instance: the instance to get the method from.  Must not be None.
    :param method_name: the method name (str) of the method to return.  Must not be None.
    :return: method with method_name on instance, None if not present.
    """
    return getattr(instance, method_name, None)
