Processor tự động freeze khi parse, run, runSync, stringify, process, or processSync được gọi

Freeze a processor.

Frozen processors are meant to be extended and not to be configured directly.

When a processor is frozen it cannot be unfrozen. New processors working the same way can be created by calling the processor.

It’s possible to freeze processors explicitly by calling .freeze(). Processors freeze automatically when .parse(), .run(), .runSync(), .stringify(), .process(), or .processSync() are called.
Nguồn:: unified - unified