```ruby
# This has been copied into Content Tagger, pending a decision on where it should live.
# If you're changing it, please consider handling the common case.

# Recursive parser for publishing-api Taxon data
module Taxonomy
  class Tree
    attr_reader :root_taxon

    def initialize(expanded_root_taxon_hash)
      @root_taxon = build_taxon(expanded_root_taxon_hash)
      root_taxon.children = parse_taxons(
        root_taxon,
          expanded_root_taxon_hash['expanded_links_hash']
      )
    end

  private

    def build_taxon(taxon_hash)
      Taxon.new(title: taxon_hash['title'],
                base_path: taxon_hash['base_path'],
                content_id: taxon_hash['content_id'],
                phase: taxon_hash['phase'],
                visible_to_departmental_editors: !!taxon_hash.dig('details', 'visible_to_departmental_editors'))
    end

    def parse_taxons(parent, item_hash)
      child_nodes(item_hash).map do |child|
        build_taxon(child).tap do |taxon|
          taxon.parent_node = parent
          taxon.children = parse_taxons(taxon, child)
        end
      end
    end

    def child_nodes(item_hash)
      children = item_hash.dig('links', 'child_taxons') ||
        item_hash.dig('expanded_links', 'child_taxons') || []
      children.sort_by { |hsh| hsh.fetch('title') }
    end
  end
end
```

Change indentation in Tree class
user
```ruby
# This has been copied into Content Tagger, pending a decision on
# where it should live.  If you're changing it, please consider
# handling the common case.

# Recursive parser for publishing-api Taxon data
module Taxonomy
  class Tree
    attr_reader :root_taxon

    def initialize(expanded_root_taxon_hash)
      @root_taxon = build_taxon(expanded_root_taxon_hash)
      root_taxon.children = parse_taxons(
        root_taxon,
          expanded_root_taxon_hash['expanded_links_hash']
      )
    end

  private

    def build_taxon(taxon_hash)
      Taxon.new(
        title: taxon_hash['title'],
        base_path: taxon_hash['base_path'],
        content_id: taxon_hash['content_id'],
        phase: taxon_hash['phase'],
        visible_to_departmental_editors: !!taxon_hash.dig(
          'details', 'visible_to_departmental_editors'
        )
      )
    end

    def parse_taxons(parent, item_hash)
      child_nodes(item_hash).map do |child|
        build_taxon(child).tap do |taxon|
          taxon.parent_node = parent
          taxon.children = parse_taxons(taxon, child)
        end
      end
    end

    def child_nodes(item_hash)
      children = item_hash.dig('links', 'child_taxons') ||
        item_hash.dig('expanded_links', 'child_taxons') || []
      children.sort_by { |hsh| hsh.fetch('title') }
    end
  end
end
```
assistant