AddDaylightSensors.rb error

edit

When trying to use this script in the OpenStudio application as an "add measure now," I get the error that my spaces "has no exterior natural lighting. No sensor will be added." However, the spaces have a thermal zone, and have outdoor boundary conditions, so I'm not sure what qualifies as having exterior natural lighting. Here is a snippet of the code from the github site, but I can't interpret it, thanks for the help!

https://github.com/NREL/OpenStudio-an...

 #eliminate spaces that don't have exterior natural lighting
  has_ext_nat_light = false
  space.surfaces.each do |surface|
    next if not surface.outsideBoundaryCondition == "Outdoors"
    surface.subSurfaces.each do |sub_surface|
      next if sub_surface.subSurfaceType == "Door"
      next if sub_surface.subSurfaceType == "OverheadDoor"
      has_ext_nat_light = true
    end
  end
  if has_ext_nat_light == false
    runner.registerWarning("Space '#{space.name}' has no exterior natural lighting. No sensor will be added.")
   next
  end