double
fun double(topFill: Fill, bottomFill: Fill, splitY: (ExtraStore) -> Number = { 0 }): LineCartesianLayer.AreaFill
Uses topFill for those areas bounded by the LineCartesianLayer line and the splitY line that are above the splitY line, and analogously for bottomFill. (The splitY line is an imaginary horizontal line whose y value is determined by splitY.)