Given a URI, returns the extension of the URI.
    
    
    
        
        | Name | 
        
        Type | 
        
        Description | 
    
    
    
    
        
            
                uri | 
            
            
            
                
String
            
             | 
            
            
            
                The Uri. | 
        
    
    
Returns:
        
    The extension of the Uri.
    
    
    
    
    
    
    
    
    
    
        Example:
        
    //extension will be "czml";
var extension = Cesium.getExtensionFromUri('/Gallery/simple.czml?value=true&example=false');