code: def make_mapcube_source(name, Spatial_Filename, spectrum):
      
      data = dict(Spatial_Filename=Spatial_Filename)
      if spectrum is not None:
          data.update(spectrum)
  
      return roi_model.MapCubeSource(name, data)
docs: Construct and return a `fermipy.roi_model.MapCubeSource` object