code: function unorderedItems(node) {
    var self = this
    var bullet = self.options.bullet
    var fn = self.visitors.listItem
    var children = node.children
    var length = children.length
    var index = -1
    var values = []
  
    while (++index < length) {
      values[index] = fn.call(self, children[index], node, index, bullet)
    }
  
    return values.join(node.spread ? blank : lineFeed)
  }
docs: Visit unordered list items.  Uses `options.bullet` as each item’s bullet.