def __init__(self, subscription_html=None):
self._subscription_html = None<EOL>if subscription_html is not None:<EOL><INDENT>self.subscription_html = subscription_html<EOL><DEDENT>
Create a SubscriptionHtml object

        :param subscription_html: Html to be appended to the email, with the
                                  subscription tracking link. You may control
                                  where the link is by using the tag <% %>
        :type subscription_html: string, optional