'Generates a stickiness policy with sticky session lifetimes controlled
by the lifetime of the browser (user-agent) or a specified expiration
period. This policy can only be associated only with HTTP listeners.
When a load balancer implements this policy, the load balancer uses a
special cookie to track the backend server instance for each request.
When the load balancer receives a request, it first checks to see if
this cookie is present in the request. If so, the load balancer sends
the request to the application server specified in the cookie. If not,
the load balancer sends the request to a server that is chosen based on
the existing load balancing algorithm.
A cookie is inserted into the response for binding subsequent requests
from the same user to that server. The validity of the cookie is based
on the cookie expiration time, which is specified in the policy
configuration.
None may be passed for cookie_expiration_period.'

def create_lb_cookie_stickiness_policy(self, cookie_expiration_period, lb_name, policy_name):

    params = {'LoadBalancerName': lb_name, 'PolicyName': policy_name}
    if (cookie_expiration_period is not None):
        params['CookieExpirationPeriod'] = cookie_expiration_period
    return self.get_status('CreateLBCookieStickinessPolicy', params)
