def process
      current_node = @instance.current_node
      return unless current_node
      child_node = current_node.send @child_node_name
      @instance.process_with_other_node child_node do
        @instance.instance_eval &@block
      end
    end
def process
      current_node = @instance.current_node
      return unless current_node
      child_node = current_node.send @child_node_name
      @instance.process_with_other_node child_node do
        @instance.instance_eval &@block
      end
    end
Initialize a scope

 @param instance [Synvert::Core::Rewriter::Instance]
 @param child_node_name [String]
 @param block [Block]
 Go to a child now, then run the block code with the the child node.