     ed = atom.workspace.getActiveTextEditor()
     for sel in ed.getSelections()
       rs = @forLines ed, sel.getHeadBufferPosition().row, sel.getTailBufferPosition().row
+      continue unless rs?
       rs.map (r) -> r.toggleView()
 
   # Commands

        window.requestAnimationFrame listener

  initMarker: ->
    @marker = @editor.markBufferRange @lineRange(@start, @end)
    @marker.result = @
    @decorateMarker()
    @disposables.add @marker.onDidChange (e) => @checkMarker e


metrics = throttle metrics, 60*60*1000

resultEditorRegistry = new Set
layers = {}

module.exports =
class Result
