Bug: DataTable/TreeTable can't export cells with "null" values

Webix JS
1

This datatable export to PDF snippet shows that undefined values are exported as blanks, but null values cause an error,

Uncaught TypeError: Cannot read property ‘toString’ of null

Sometimes that data that comes from external APIs might contain a null. In that case, it would be nice if Webix exported a blank instead.

2

This problem is already fixed in dev. version.
In Webix 2.2 null value will produce an empty string ( during rendering and during data export )