human
Solve the following python programming problem given the following code:
def _create_instance_with_availability_zone(self, zone_name) : 
    def create(* args, **kwargs) : 
        self.assertIn ('availability_zone', kwargs) 
        self.assertEqual ('nova', kwargs ['availability_zone']) 
        return old_create (* args, ** kwargs) 
old_create = compute_api.API.create 
    self.stubs.Set (compute_api.API, 'create', create) 
    image_href = '76fa36fc-c930-4bf3-8c8a-ea2a2420deb6' 
    flavor_ref = (('http://localhost' + self.base_url) + 'flavors/3') 
    body = { 
        'server' : { 
            'name' : 'server_test', 
            'imageRef' : image_href, 
            'flavorRef' : flavor_ref, 
            'metadata' : { 
                'hello' : 'world', 
                'open' : 'stack', 
}, 
            'availability_zone' : flavor_ref, 
}, 
} 
    admin_context = context.get_admin_context () 
    db.service_create (admin_context, { 
        'host' : 'host1_zones', 
        'binary' : 'nova-compute', 
        'topic' : 'compute', 
        'report_count' : 0, 
}) 
    agg = db.aggregate_create (admin_context, { 
        'name' : 'agg1', 
}, { 
        'availability_zone' : 'nova', 
}) 
    db.aggregate_host_add (admin_context, agg ['id'], 'host1_zones') 
    return (self.req, body) 

    
    

    Fix the buggy line: 'availability_zone' : flavor_ref ,
assistant
#Here is Python code to fix the buggy line: 'availability_zone' : flavor_ref ,
.

'availability_zone' : zone_name ,