code: func newNode(parent *node, entry Entry) *node {
  	return &node{
  		children: [2]*node{},
  		entry:    entry,
  		parent:   parent,
  	}
  }
docs: // newNode will allocate and initialize a newNode with the provided
  // parent and entry.  Parent should never be nil, but entry may be
  // if constructing an internal node.