Function setRasterLayerTransparency

setRasterLayerTransparency(layerId, transparency): void
JMap.Map.setRasterLayerTransparency

Sets the transparency for a given raster layer
Parameters
- layerId: JId
  The JMap layer id
- transparency: number
  the new layer transparency between 0 and 1
Returns void
Throws
Error if layer is not found, not a raster layer or transparency is invalid

Example
```
// Make raster layer id=10 transparent
JMap.Map.setRasterLayerTransparency(10, 1)
```