public static function generate_font_imports() {
		$imports = '';

		$google_fonts = array();

		foreach ( pum_get_all_themes() as $theme ) {
			$google_fonts = array_merge( $google_fonts, pum_get_theme( $theme->ID )->get_google_fonts_used() );
		}

		if ( ! empty( $google_fonts ) && ! pum_get_option( 'disable_google_font_loading', false ) ) {
			$link = "//fonts.googleapis.com/css?family=";
			foreach ( $google_fonts as $font_family => $variants ) {
				if ( $link != "//fonts.googleapis.com/css?family=" ) {
					$link .= "|";
				}
				$link .= $font_family;
				if ( is_array( $variants ) ) {
					if ( implode( ',', $variants ) != '' ) {
						$link .= ":";
						$link .= trim( implode( ',', $variants ), ':' );
					}
				}
			}

			$imports = "/* Popup Google Fonts */\r\n@import url('$link');\r\n\r\n" . $imports;
		}

		$imports = apply_filters( 'pum_generate_font_imports', $imports );

		return $imports;
	}