class RBI::Rewriters::NestNonPublicMembers

def visit(node)
  return unless node
  case node
  when Tree
    public_group = VisibilityGroup.new(Public.new)
    protected_group = VisibilityGroup.new(Protected.new)
    private_group = VisibilityGroup.new(Private.new)
    node.nodes.dup.each do |child|
      visit(child)
      next unless child.is_a?(Attr) || child.is_a?(Method)
      child.detach
      case child.visibility
      when Protected
        protected_group << child
      when Private
        private_group << child
      else
        public_group << child
      end
    end
    node << public_group unless public_group.empty?
    node << protected_group unless protected_group.empty?
    node << private_group unless private_group.empty?
  end
end