code: function _orphans (options) {
    options.hash.memberof = undefined
    return _identifiers(options).filter(function (identifier) {
      if (identifier.kind === 'external') {
        return identifier.description && identifier.description.length > 0
      } else {
        return true
      }
    })
  }
docs: Returns an array of the top-level elements which have no parents. Output only includes externals which have a description.
  @returns {array}
  @static
  @category Returns list