code: protected OMVRBTreeEntry<K, V> getFirstEntry() {
      OMVRBTreeEntry<K, V> p = root;
      if (p != null) {
        if (p.getSize() > 0)
          pageIndex = 0;
  
        while (p.getLeft() != null)
          p = p.getLeft();
      }
      return p;
    }
docs: Returns the first Entry in the OMVRBTree (according to the OMVRBTree's key-sort function). Returns null if the OMVRBTree is
  empty.