lib/TypeParser.js
function idOptions (id, options) {
  const _key = options._key == null
    ? '[' + id + ']'
    : options._key + '[' + id + ']'
  return Object.assign({}, options, { _key: _key })
}
function idOptions (id, options) {
  const _key = options._key == null
    ? '[' + id + ']'
    : options._key + '[' + id + ']'
  return Object.assign({}, options, { _key: _key })
}
function idOptions ( id , options ) { const _key = options . _key == null ? '[' + id + ']' : options . _key + '[' + id + ']' return Object . assign ( { } , options , { _key : _key } ) }
Add array index to options.
Add array index to options .