title: Pick random node from tree
body: <p>I have a tree data structure, where each node can have multiple children. So there is not only a left and a right, but either less or even way more.
  Now I want to pick a node from this tree randomly. For every node, I know how many children are connected to it. But how can I pick them in a random fashion, uniformly would be awesome. Any ideas? I found solutions for the case of only a left and a right child, but as I said, that is not really applicable here.</p>