Updates badge text and style of the sidebar node with 
id.
    setCount(id, count, [className], [style])
    
    
        | id | string, id of the sidebar node | 
    
        | count | text, count for the sidebar node, can be plain text | 
    
        | className | text, (optional) custom class for the badge | 
    
        | style | text, (optional) additional style for the badge | 
    
 
Returns undefined.
Description
The first argument 
id is the id of the sidebar node you used when you created sidebar.
If you have toolbar defined in the following way:
You can update badge by