Map: NodeCategoryProperty is Type of number

Hi, i just evaluate gojs and i try something.
I want set the nodeCategoryProperty with a property of type number.
But i receive the error:12 caused by: getCategoryForNodeData found a non-string category for [object Object]: 0

It is not possible to set the keytype of a map with the type ‘number’?

Maps can certainly accept numbers as keys. However category values must be strings: Model | GoJS API and Part | GoJS API

You could convert your numbers to strings and then parse the strings when needed.