code: public OMVRBTreeEntry<K, V> getFirstInMemory() {
      OMVRBTreeEntry<K, V> node = this;
      OMVRBTreeEntry<K, V> prev = this;
  
      while (node != null) {
        prev = node;
        node = node.getPreviousInMemory();
      }
  
      return prev;
    }
docs: Returns the first Entry only by traversing the memory, or null if no such.