private final Tree linkUp(Tree a_preceding, int a_level){
Tree node = (Tree)i_template.read(i_bytes);
i_current++;
node._preceding = a_preceding;
node._subsequent = linkDown(a_level + 1);
node.calculateSize();
if(i_current < i_size){
return linkUp(node, a_level - 1);
}
return node;