function assertArg(arg, name, reason) {
  if (!arg) {
    throw ngMinErr('areq', 'Argument \'{0}\' is {1}', (name || '?'), (reason || 'required'));
  }
  return arg;
}
The software constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.