DistributedLock with concurrency handling

DistributedLock.cs

try
{
  var response = await collection.FindOneAndUpdateAsync<LockModel>( 
    // Collapsed  
  );

  // If the result of the FindOneAndUpdateAsync is null, then that means there was no record 
  // before we ran our statement, so we now have the lock.
  // If the result is not null, then it means a document for the lock already existed, so someone else has the lock.
  if (response == null)
  {
    return true;
  }

  return false;
}
catch (MongoCommandException ex)
{
  // 11000 == MongoDB Duplicate Key error
  if (ex.Code == 11000)
  {
    // Two threads have tried to acquire a lock at the exact same moment on the same key, 
    // which will cause a duplicate key exception in MongoDB.
    // So this thread failed to acquire the lock.
    return false;
  }

  throw;
}