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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def simple_getter(queryset, object_regex=None, lookup_field=None):
    ''' Returns simple object_getter function for use with PluggableSite.
    It takes 'queryset' with QuerySet or Model instance, 'object_regex' with
    url regex and 'lookup_field' with lookup field.
    '''
    object_regex = object_regex or r'\d+'
    lookup_field = lookup_field or 'pk'

    if isinstance(queryset, models.Model):
        qs = queryset._default_manager.all()
    elif isinstance(queryset, QuerySet) or isinstance(queryset, models.Manager):
        qs = queryset

    def object_getter(object_id):
        return qs.get(**{lookup_field: object_id})
    object_getter.regex = "(?P<object_id>%s)" % object_regex

    return object_getter