V readValueUnderLock(HashEntry<V> e) {
      lock();
      try {
        return e.value;
      } finally {
        unlock();
      }
    }
Reads value field of an entry under lock. Called if value field ever appears to be null. This
is possible only if a compiler happens to reorder a HashEntry initialization with its table
assignment, which is legal under memory model but is not known to ever occur.
geode-core/src/main/java/org/apache/geode/internal/ObjIdConcurrentMap.java