docs: function transform(context, file, fileSet, next) {
    if (stats(file).fatal) {
      next()
    } else {
      debug('Transforming document `%s`', file.path)
      context.processor.run(context.tree, file, onrun)
    }
  
    function onrun(error, node) {
      debug('Transformed document (error: %s)', error)
      context.tree = node
      next(error)
    }
  }