code: func (a Nodes) Filter(n *Node) []*Node {
  	other := make([]*Node, 0, len(a))
  	for i := range a {
  		if a[i] != n {
  			other = append(other, a[i])
  		}
  	}
  	return other
  }
docs: // Filter returns a new list of nodes with node removed.