Extraneous Number cast

[Harbs]

The following code:
var range:XML;
// etc.
var childLen:int = range.children().length();

compiles to:
var /** @type {XML} */ range;
// etc.
var /** @type {number} */ childLen = Number(range.children().length());

I don’t see why the Number() cast is being added both childLen and 
children().length() are typed as ints.

Am I correct in assuming that this is a bug?

Harbs