Stack context error

wtf.as

package
{
	import flash.display.Sprite;

	public class FunctionCallTests extends Sprite
	{
		public function FunctionCallTests()
		{
			traceMyArgs( $[this, "yo"] );
		}

		public function traceMyArgs( ...args ):void
		{
			trace( "Yeah!", args );
		}

		public function get yo():FunctionCallTests
		{
			trace( "FunctionCallTests.yo!" );
			return this;
		}
	}
}

class $
{
	public static function traceMyArgs( ...args ):void
	{
		trace( "O_o", args );
	}
}

and the output is:

[trace] FunctionCallTests.yo!
[trace] O_o [object FunctionCallTests]