Duplicate react keys cause exception when program requests multiple canvases

[Paul Sonnentag]

I found a bug when requesting multiple canvases like this:

 var canvas2 = await paper.get('canvas');
 var canvas = await paper.get('canvas', { number: 42 }); // some other paper number

I get the following errror

The cause is that the canvases have duplicate keys which leads to bugy behaviour.

Interestingly it works when requesting the canvases the other way around:

 var canvas = await paper.get('canvas', { number: 42 }); // some other paper number
 var canvas2 = await paper.get('canvas');

I've fixed the issue by generating unique keys.