WP_Error::copy_errors( WP_Error $from, WP_Error $to )

	protected static function copy_errors( WP_Error $from, WP_Error $to ) {
		foreach ( $from->get_error_codes() as $code ) {
			foreach ( $from->get_error_messages( $code ) as $error_message ) {
				$to->add( $code, $error_message );
			}

			foreach ( $from->get_all_error_data( $code ) as $data ) {
				$to->add_data( $data, $code );
			}
		}
	}