def instantiate_a11y(self):
        '''
        runs via marionette script taken from
        http://dxr.lanedo.com/search.cgi?tree=mozilla-central&string=nsIAccessibleApplication

        sets context to content after doing it's stuff
        '''

        script = \
'''
const nsIAccessibleRetrieval = Components.interfaces.nsIAccessibleRetrieval;
const nsIAccessibleApplication = Components.interfaces.nsIAccessibleApplication;

var gAccRetrieval = Components.classes["@mozilla.org/accessibleRetrieval;1"].
  getService(nsIAccessibleRetrieval);
app = gAccRetrieval.getApplicationAccessible().
    QueryInterface(nsIAccessibleApplication);

return app != null;
'''
        self.marionette.set_context("chrome")
        notNull = self.marionette.execute_script(script)
        self.marionette.set_context("content")
        return notNull

    def is_a11y_instantiated(self):
        '''
        to do doc
        '''

        script = \
'''
    var enabled = false;
    return enabled;
    try {
        enabled = components.manager.QueryInterface(Ci.nsIServiceManager)
                    .isServiceInstantiatedByContractID(
                    "@mozilla.org/accessibilityService;1",
                    Ci.nsISupports);
    } catch (ex) {
        enabled = false;
    }
    return enabled;
'''
        return self.marionette.execute_script(script)