We now have this:
```ruby
def children
  @children ||= {}
end

def children=(kids)
  @children = kids
end
```

Why not replace both of these with `attr_accessor`?
```ruby
attr_accessor :children
```

Is there a real need to initialize `@children` with a hash?

Since AA depends on Rails, any places in the code base that checks if there are any children can do this instead:
```ruby
children.present? # same as !children.blank?
```