code: func cloneTreapNode(node *treapNode) *treapNode {
  	return &treapNode{
  		key:      node.key,
  		value:    node.value,
  		priority: node.priority,
  		left:     node.left,
  		right:    node.right,
  	}
  }
docs: // cloneTreapNode returns a shallow copy of the passed node.