_linkNodes = function _linkNodes(node, parent) {
    // remove node from root list of heap
    node.left.right = node.right;
    node.right.left = node.left; // make node a Child of parent

    node.parent = parent;

    if (!parent.child) {
      parent.child = node;
      node.right = node;
      node.left = node;
    } else {
      node.left = parent.child;
      node.right = parent.child.right;
      parent.child.right = node;
      node.right.left = node;
    } // increase degree[parent]


    parent.degree++; // set mark[node] false

    node.mark = false;
  }
Make the first node a child of the second one. Running time: O(1) actual.
@memberof FibonacciHeap