def find_hash_children(toc, title)
      toc.each_key do |key|
        next if toc[key].nil?
        toc[key].each do |item|
          next unless item.is_a?(Hash)
          if item[title]
            children = item.values.flatten
            return children
          end
        end
      end
      # Found no children
      Array.new
    end
def find_hash_children(toc, title)
      toc.each_key do |key|
        next if toc[key].nil?
        toc[key].each do |item|
          next unless item.is_a?(Hash)
          if item[title]
            children = item.values.flatten
            return children
          end
        end
      end
      # Found no children
      Array.new
    end
Given a category file that's a hash, this method finds
 the children of an item, probably a map topic

 toc - the hash containing the table of contents
 title - the text title to return the children of

 Returns a flattened array of all descendants which could be empty.