getSelectedCell() not working as documented for multiple cell selection

The documentation states that if multiple cells are selected, getSelectedCells() will return an array of CellData objects.  However I am finding that this is not the case, either in the codePen example linked with the documentation, or in my implementation, which always returns an array of length 1 for both rows and columns, regardless of how many cells are selected e.g., as shown in below output.  Is it possible to make it work as documented, or alternatively to implement a getSelectedRows() method?  
 

1. rows: Array(1)
   1. 0: {caption: “Configuration.Databases.Smoke”, uniqueName: “name.Configuration.Databases.Smoke”, hierarchyCaption: “name”, hierarchyUniqueName: “name”}
   2. length: 1
   3. __proto__: Array(0)
2. type: “value“
3. value: 0
4. width: 225
5. x: 259
6. y: 85
7. __proto__: Object