https://learn.microsoft.com/en-us/dotnet/api/system.threading.readerwriterlock.downgradefromwriterlock?view=netframework-4.8.1&viewFallbackFrom=net-10.0
ReaderWriterLock.DowngradeFromWriterLock(LockCookie) Method (System.Threading) | Microsoft Learn
Restores the lock status of the thread to what it was before UpgradeToWriterLock(Int32) was called.
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