public function __construct()
 {
     $this->fontList = WpsGenerateThemeFonts::get_instance()->return_font_list();
 }
<?php

/**
 *  Typography settings
 *
 * @package wps_prime
 */
/* Add fonts */
$myfont = WpsGenerateThemeFonts::get_instance();
$myfont->add_font('Open Sans', 'sans-serif', 'https://fonts.googleapis.com/css?family=Open+Sans:300,400,600,800', 'font-weight: 300', 'font-weight: 600');
$myfont->add_font('Merriweather', 'serif', 'https://fonts.googleapis.com/css?family=Merriweather:300,400,700,900', 'font-weight: 300', 'font-weight: 900');
$myfont->add_font('Raleway', 'sans-serif', 'https://fonts.googleapis.com/css?family=Raleway:200,300,400,600,900', 'font-weight: 300', 'font-weight: 600');
$myfont->add_font('Lato', 'sans-serif', 'https://fonts.googleapis.com/css?family=Lato:100,300,400,700,900', 'font-weight: 300', 'font-weight: 600');
$myfont->add_font('Roboto', 'sans-serif', 'https://fonts.googleapis.com/css?family=Roboto:400,100,300,500,700,900', 'font-weight: 300', 'font-weight: 600');
$myfont->add_font('Source Sans Pro', 'sans-serif', 'https://fonts.googleapis.com/css?family=Source+Sans+Pro:200,300,400,600,700,900', 'font-weight: 300', 'font-weight: 900');
$myfont->add_font('PT Sans', 'sans-serif', 'https://fonts.googleapis.com/css?family=PT+Sans:400,700', 'font-weight: 400', 'font-weight: 700');