PolyStyle override LineStyle on LineString

when Style have PolyStyle.outline = 0, geojson.properties['stroke-opacity'] will be 0.
but in LineString case, it should not use the PolyStyle

<?xml version="1.0" encoding="UTF-8"?> <kml xmlns="http://www.opengis.net/kml/2.2" xmlns:gx="http://www.google.com/kml/ext/2.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.opengis.net/kml/2.2 http://schemas.opengis.net/kml/2.2.0/ogckml22.xsd http://www.google.com/kml/ext/2.2 http://code.google.com/apis/kml/schema/kml22gx.xsd"> <Document id="rcrossec"> <name>rcrossec</name> <Snippet></Snippet> <Folder id="FeatureLayer0"> <name>rcrossec</name> <Snippet></Snippet> <Placemark id="ID_00000"> <name>114000_000</name> <Snippet></Snippet> <description></description> <styleUrl>#LineStyle00</styleUrl> <MultiGeometry> <LineString> <extrude>0</extrude> <altitudeMode>clampedToGround</altitudeMode> <coordinates> 121.4214319507,25.17652710587822,0 121.4163445506372,25.16918616964401,0</coordinates> </LineString> </MultiGeometry> </Placemark> </Folder> <Style id="LineStyle00"> <LabelStyle> <color>00000000</color> <scale>0.000000</scale> </LabelStyle> <LineStyle> <color>ff992100</color> <width>9.000000</width> </LineStyle> <PolyStyle> <color>ff7faa55</color> <outline>0</outline> </PolyStyle> </Style> </Document> </kml>

Start with the supplied KML example and trace how the converter handles LineString styles, especially PolyStyle.outline and the generated stroke-opacity property. Confirm the existing behavior with a focused test or reproduction, then ensure LineString rendering uses LineStyle rather than PolyStyle; done means the example retains the LineStyle opacity.