docs: function LabelAtlas (opts) {
      LabelAtlas.superclass.constructor.call(this, {
          file: opts.charMapFile,
          itemWidth: opts.itemWidth,
          itemHeight: opts.itemHeight,
          itemsToRender: opts.string.length,
          size: new geo.Size(opts.itemWidth * opts.string.length, opts.itemHeight)
      })
  
      events.addPropertyListener(this, 'string', 'change', this.updateAtlasValue.bind(this))
  
      this.mapStartChar = opts.startCharMap.charCodeAt(0)
      this.string = opts.string
  
      this.contentSize = new geo.Size(opts.itemWidth * this.string.length, opts.itemHeight)
  }