public static function get_ip_address() {
		if ( isset( $_SERVER['HTTP_X_REAL_IP'] ) ) {
			return sanitize_text_field( wp_unslash( $_SERVER['HTTP_X_REAL_IP'] ) );
		} elseif ( isset( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
			// Proxy servers can send through this header like this: X-Forwarded-For: client1, proxy1, proxy2
			// Make sure we always only send through the first IP in the list which should always be the client IP.
			return (string) rest_is_ip_address( trim( current( preg_split( '/,/', sanitize_text_field( wp_unslash( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) ) ) ) );
		} elseif ( isset( $_SERVER['REMOTE_ADDR'] ) ) {
			return sanitize_text_field( wp_unslash( $_SERVER['REMOTE_ADDR'] ) );
		}
		return '';
	}