magnacarto/render/mapnik/test/map.xml

<?xml version="1.0" encoding="utf-8"?>
<Map srs="epsg:4326" maximum-extent="-180,-90,180,90" background-color="steelblue">

    <Style name="styleA">
        <Rule>
            <PolygonSymbolizer fill="rgba(255, 0, 0, 0.5)" />
        </Rule>
    </Style>

    <Style name="styleB">
        <Rule>
            <PolygonSymbolizer fill="rgba(0, 255, 0, 0.5)" />
        </Rule>
    </Style>

    <Style name="styleC">
        <Rule>
            <PolygonSymbolizer fill="rgba(0, 0, 255, 0.5)" />
        </Rule>
    </Style>

    <Style name="styleD">
        <Rule>
            <PolygonSymbolizer fill="rgba(0, 255, 255, 0.5)" />
        </Rule>
    </Style>

    <Layer name="layerA" srs="epsg:4326">
        <StyleName>styleA</StyleName>
        <Datasource>
            <Parameter name="file">map.geojson</Parameter>
            <Parameter name="type">geojson</Parameter>
        </Datasource>
    </Layer>

    <Layer name="layerB" srs="epsg:4326">
        <StyleName>styleB</StyleName>
        <Datasource>
            <Parameter name="file">map.geojson</Parameter>
            <Parameter name="type">geojson</Parameter>
        </Datasource>
    </Layer>

    <Layer name="layerC" srs="epsg:4326" status="on">
        <StyleName>styleC</StyleName>
        <Datasource>
            <Parameter name="file">map.geojson</Parameter>
            <Parameter name="type">geojson</Parameter>
        </Datasource>
    </Layer>

    <Layer name="__OFF__layerD" srs="epsg:4326">
        <StyleName>styleD</StyleName>
        <Datasource>
            <Parameter name="file">map.geojson</Parameter>
            <Parameter name="type">geojson</Parameter>
        </Datasource>
    </Layer>

</Map>