Redundant/wrong heading output for style definition

[wguttmn]

The following (Kotlin) code snippet

val normalMultitrackStyle = document.createAndAddStyle().withId("multiTrack_n")
normalMultitrackStyle.createAndSetIconStyle().createAndSetIcon().withHref("https://earth.google.com/images/kml-icons/track-directional/track-0.png")
normalMultitrackStyle.createAndSetLineStyle().withColor("99ffac59").withWidth(6.0)

produces output as follows (just showing the relevant fragment):

<kml:Style id="multiTrack_n">
            <kml:IconStyle>
                <kml:scale>0.0</kml:scale>
                <kml:heading>0.0</kml:heading>
                <kml:Icon>
                    <kml:href>https://earth.google.com/images/kml-icons/track-directional/track-0.png</kml:href>
                </kml:Icon>
            </kml:IconStyle>
            <kml:LineStyle>
                <kml:color>99ffac59</kml:color>
                <kml:width>6.0</kml:width>
            </kml:LineStyle>
        </kml:Style>

Any idea why this includes the heading element, as I am not setting this at all ?