How to use the ghost/utils/mobile.matches function in ghost

this.set('changeLayout', function changeLayout() {
            if (mobileQuery.matches) {
                // transitioned to mobile layout, so show content
                self.showContent();
            } else {
                // went from mobile to desktop
                self.showAll();
            }
        });
    }.on('init'),

this.set('changeLayout', function changeLayout() {
            if (mobileQuery.matches) {
                // transitioned to mobile layout, so show content
                self.showContent();
            } else {
                // went from mobile to desktop
                self.showAll();
            }
        });
    }.on('init'),

showContent: function () {
        if (mobileQuery.matches) {
            this.get('parentView').showContent();
        }
    }.on('didInsertElement')
});

showMenu: function () {
        if (mobileQuery.matches) {
            this.get('parentView').showMenu();
        }
    }.on('didInsertElement')
});

showContent: function () {
        if (mobileQuery.matches) {
            this.get('parentView').showContent();
        }
    }.on('didInsertElement')
});

showMenu: function () {
        if (mobileQuery.matches) {
            this.get('parentView').showMenu();
        }
    }.on('didInsertElement')
});

showMenu: function () {
        if (mobileQuery.matches) {
            this.get('parentView').showMenu();
        }
    }.on('didInsertElement')
});

Ember.run(function () {
                if (mobileQuery.matches) {
                    self.set('controller.showGlobalMobileNav', false);
                }
            });
        });

.then(function () {
                if (!mobileQuery.matches) {
                    self.transitionTo('settings.general');
                }
            });
    },

showContent: function () {
        if (mobileQuery.matches) {
            var parent = this.get('parentView');
            if (parent.showContent) {
                parent.showContent();
            }
        }
    }.on('didInsertElement')
});