<Map srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over" background-color="rgba(255,255,255,1)">
<Style name="testmerc" filter-mode="first" >
  <Rule>
    <RasterSymbolizer opacity="1" scaling="bilinear" />
  </Rule>
</Style>
<Layer name="testmerc"
  srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over">
    <StyleName>testmerc</StyleName>
    <Datasource>
       <!-- https://github.com/mapnik/mapnik/issues/1508 -->
       <!-- note: this mis-reports it is premultiplied - it is not -->
       <Parameter name="file">../../data/raster/river_merc.tiff</Parameter>
       <Parameter name="extent">-8249238.098993212,-486119.1339340762,-8024337.037783274,-302066.9754826002</Parameter>
       <Parameter name="type">raster</Parameter>
    </Datasource>
  </Layer>
</Map>