code: function descendants (options) {
    var min = typeof options.hash.min !== 'undefined' ? options.hash.min : 2
    delete options.hash.min
    options.hash.memberof = this.id
    var output = []
    function iterate (childrenList) {
      if (childrenList.length) {
        childrenList.forEach(function (child) {
          output.push(child)
          iterate(_children.call(child, options))
        })
      }
    }
    iterate(_children.call(this, options))
    if (output.length >= (min || 0)) return output
  }
docs: return a flat list containing all decendants
  @param [sortBy] {string} - "kind"
  @param [min] {number} - only returns if there are `min` children
  @this {identifier}
  @returns {identifier[]}
  @static