Missing lock guard in THashTable

While browsing the source code, I noticed that there isn't a lock guard in THashTable at the following location: https://github.com/root-project/root/blob/331efa4c00fefc38980eaaf7b41b8e95fcd1a23b/core/cont/src/THashTable.cxx#L254

But lock guard exists in the other methods. Thought I'd just ask if this was intentional or not??