function of finding a node

[nir0]

in the code we got:

  if(typeof insertionNode === 'function') {
    if(insertionTraversal) {
      console.warn('association-insertion-traversal is ignored, because association-insertion-node is given as a function.');
    }
    return insertionNode(btn);
  }

how exactly do you pass a function to this data attribute?

i've tried multiple times, it always stores function as a string.