def each
      return to_enum(__callee__) unless block_given?

      node = self
      loop do
        yield node
        break unless (node = node.next_node)
      end
    end
def each
      return to_enum(__callee__) unless block_given?

      node = self
      loop do
        yield node
        break unless (node = node.next_node)
      end
    end
Implements the Enumerable interface to walk through an entire tree.

 @return [Enumerator, HamlLint::Tree::Node]