code: function transformTree (object, fn) {
    const label = fn(object).trim()
    if (object.children) {
      return {
        label: label,
        nodes: object.children.map(function (child) {
          return transformTree(child, fn)
        })
      }
    } else {
      return label
    }
  }
docs: Transfrom an object hierarchy into `archy`'s format
  
  Transform a tree-structure of the form
  ```
  {
  prop1: 'value',
  prop2: 'value',
  ...,
  children: [
  {
  prop1: 'value',
  propt2: 'value',
  ...,
  children: ...
  }
  ]
  }
  ```
  Into an [archy](https://www.npmjs.com/package/archy)-compatible format, by passing each node to a block-helper function.
  The result of the function should be a string which is then used as label for the node.
  
  @param {object} object the tree data
  @param fn the block-helper function (options.fn) of Handlebars (http://handlebarsjs.com/block_helpers.html)
  
  @access private