Cannot convert value of type '[NSObject : AnyObject]' to type 'NSMutableDictionary' in coercion
<p>Here's code that produces this error.</p>

<pre><code>for dic: [NSObject : AnyObject] in items as! [[NSObject : AnyObject]] {
            if (dic["Value"] != nil) {
                values.append((dic["Value"] as! String))
                var dict = dic as NSMutableDictionary
                if ((dic["Details"] as! String) == "") {
                    hasValues = false
                    dict["ISRequired"] = Int(true)
                } else {
                    (dic as NSMutableDictionary)["ISRequired"] = Int(false)
                }
            }
        }
</code></pre>

<p>Error explains that I can't convert to mutable dictionary.</p>