How to use the superdesk-core/spec/helpers/utils.screenshot function in superdesk-core

onPrepare: function() {
        require('./client/spec/helpers/setup')({fixture_profile: 'planning_prepopulate_data'});

        // so it can be used without import in tests
        // useful when debugging on CI server
        browser.screenshot = require('superdesk-core/spec/helpers/utils').screenshot;

        var reporters = require('jasmine-reporters');

        jasmine.getEnv().addReporter(
            new reporters.JUnitXmlReporter({
                savePath: 'e2e-test-results',
                consolidateAll: true,
            })
        );
        function CustomReporter() {
            this.specDone = function(result) {
                if (result.failedExpectations.length > 0) {
                    browser.screenshot(result.fullName.replace(/[^\w]+/g, '-'));
                }
            };
        }