def relink_parent(node)
      if @parent
        if @parent.smaller == self
          @parent.set_link('@smaller', node)
        elsif @parent.equal == self
          @parent.set_link('@equal', node)
        elsif @parent.larger == self
          @parent.set_link('@larger', node)
        else
          PEROBS.log.fatal "Cannot relink unknown child node with address " +
            "#{node.node_address} from #{parent.to_s}"
        end
      else
        if node
          @tree.set_root(node)
          node.parent = nil
        else
          set_size_and_address(0, 0)
        end
      end
    end
def relink_parent(node)
      if @parent
        if @parent.smaller == self
          @parent.set_link('@smaller', node)
        elsif @parent.equal == self
          @parent.set_link('@equal', node)
        elsif @parent.larger == self
          @parent.set_link('@larger', node)
        else
          PEROBS.log.fatal "Cannot relink unknown child node with address " +
            "#{node.node_address} from #{parent.to_s}"
        end
      else
        if node
          @tree.set_root(node)
          node.parent = nil
        else
          set_size_and_address(0, 0)
        end
      end
    end
Replace the link in the parent node of the current node that points to
 the current node with the given node.
 @param node [SpaceTreeNode]