check if style (font-awesome) was loaded with the theme files

//load font awesome if not loaded with the theme files
function check_font_awesome() {
    global $wp_styles;
    $srcs = array_map('basename', (array) wp_list_pluck($wp_styles->registered, 'src') );
    if ( in_array('font-awesome.css', $srcs) || in_array('font-awesome.min.css', $srcs)  ) {
        /* echo 'font-awesome.css registered'; */
    } else {
        wp_enqueue_style( 'local-business-schema-fonts', PLUGIN_FOLDER  . '/assets/fonts/font-awesome/css/font-awesome.min.css', array(), '', 'screen' );
    }
}
add_action('wp_enqueue_scripts', 'check_font_awesome', 99999);