carto/test/rendering-mss/basic_attachment_internal_before.xml

<Style name="style" filter-mode="first">
  <Rule>
    <LineSymbolizer stroke="#da70d6" stroke-width="10" />
  </Rule>
</Style>
<Style name="style-outline" filter-mode="first">
  <Rule>
    <LineSymbolizer stroke="#f0f8ff" stroke-width="5" />
  </Rule>
</Style>