code: function wrap(nodes, loose) {
    var result = []
    var index = -1
    var length = nodes.length
  
    if (loose) {
      result.push(u('text', '\n'))
    }
  
    while (++index < length) {
      if (index) {
        result.push(u('text', '\n'))
      }
  
      result.push(nodes[index])
    }
  
    if (loose && nodes.length !== 0) {
      result.push(u('text', '\n'))
    }
  
    return result
  }
docs: Wrap `nodes` with newlines between each entry.  Optionally adds newlines at the start and end.