Stylesheets and QFontComboBox Sub-control

[been_1990]

I've been trying to use a picture for the background of the "down-arrow" of QFontComboBox. If I try

QFontComboBox::arrow_down{
border:none;
 background-image: url("arrow.png" );
}

QFontComboBox::arrow_down{
border:none;
 background-image: url("arrow.png" );
}

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Nothing happens. I tried that on a regular QComboBox and no image is displayed, but using gradients work fine.
The effect I want to achieve with the font combobox, is a no-border box, not even the down-arrow. Just everything plain.