add_action( 'init', 'stop_heartbeat', 1 );
function stop_heartbeat() {
    wp_deregister_script('heartbeat');
}

add_filter( 'wp_lazy_loading_enabled', '__return_true' );

function defer_parsing_of_js( $url ) {
    if ( FALSE === strpos( $url, '.js' ) ) return $url;
    if ( strpos( $url, 'jquery.js' ) ) return $url;
    return "$url' defer ";
}
add_filter( 'clean_url', 'defer_parsing_of_js', 11, 1 );

function remove_css_js_ver( $src ) {
    if( strpos( $src, '?ver=' ) )
        $src = remove_query_arg( 'ver', $src );
    return $src;
}
add_filter( 'style_loader_src', 'remove_css_js_ver', 10, 2 );
add_filter( 'script_loader_src', 'remove_css_js_ver', 10, 2 );

remove_action('wp_head', 'print_emoji_detection_script', 7);
remove_action('wp_print_styles', 'print_emoji_styles');