public function get_header_markup()
This method is used to return header markup when building layouts directly inside theme template files, and should only be used after the init_page() method has been called.
This method accepts no arguments.
If the $standalone argument was passed as false to init_page() (or no value was specified), this method will return anything added to the class' $html property by the build_header() method. If $standalone was passed as true, all markup added to the $html, $scripts, and $modals properties will be returned.
Below is a basic example of a page template built using get_header_markup():