KeyModifier doesn't seem to work

I have a File Save Dialog. The file name field is already populated. I want to select all of the text, so I can delete it. Manually, holding down Control+Shift+End works. However, when I try the same thing in Sikuli it is as if it is only holding down Control+End.

Here is the code I am using:

type(Key.END, KeyModifier.SHIFT + KeyModifier.CTRL)

Is this a bug or is there a different way to do it that works?