code: function transformer(node) {
      var result = util(node, {
        heading: heading,
        maxDepth: depth,
        tight: tight
      })
  
      if (result.index === null || result.index === -1 || !result.map) {
        return
      }
  
      /* Replace markdown. */
      node.children = [].concat(
        node.children.slice(0, result.index),
        result.map,
        node.children.slice(result.endIndex)
      )
    }
docs: /* Adds an example section based on a valid example
  JavaScript document to a `Usage` section.