code: function label(node) {
    var type = node.referenceType
  
    if (type === shortcut) {
      return ''
    }
  
    return (
      leftSquareBracket +
      (type === collapsed ? '' : node.label || node.identifier) +
      rightSquareBracket
    )
  }
docs: Stringify a reference label. Because link references are easily, mistakingly, created (for example, `[foo]`), reference nodes have an extra property depicting how it looked in the original document, so stringification can cause minimal changes.