example update_if_exists failure

test_hostrecord.py

from infoblox_client import objects, connector
import getpass

def main():
	username = input('Username > ')
	password = getpass.getpass('Password > ')

	conn = connector.Connector({'host':'infoblox.example.com','username':username,'password':password,
			'ssl_verify':False,'wapi_version':"1.7"})

	host_record = objects.HostRecord

	host_record.create(conn, ip=objects.IP.create('8.8.8.8'), view="Public View (PNS)", name="test.example.net",
			configure_for_dns=True, ttl=None, comment=None,
			extattrs=None)
	#fails in wapi 1.7.1
	host_record.create(conn, ip=objects.IP.create('8.8.4.4'), view="Public View (PNS)", name="test.example.net",
			configure_for_dns=True, ttl=None, comment=None,
			extattrs=None, update_if_exists=True)

main()