void GetFirst(Iterator& a_it) {
a_it.Init();
Node* first = m_root;
while (first) {
if (first->IsInternalNode() && first->m_count > 1) {
a_it.Push(first, 1); // Descend sibling branch later
} else if (first->IsLeaf()) {
if (first->m_count) {
a_it.Push(first, 0);
}
break;
}
first = first->m_branch[0].m_child;
}
}
