code: protected MkTabEntry createNewLeafEntry(DBID id, O object, double parentDistance) {
      return new MkTabLeafEntry(id, parentDistance, knnDistances(object));
    }
docs: Creates a new leaf entry representing the specified data object in the
  specified subtree.
  
  @param object the data object to be represented by the new entry
  @param parentDistance the distance from the object to the routing object of
  the parent node