create_nested_structure.rb

facts = [
  {
    fact_category: {
      name: "Cars",
      code: "cars",
      protected: false,
      enabled: true,
      system: true,
      fact_types: [
        {
          code: "st",
          name: "station codes",
          fact_values: [],
        },
      ],
    },
  }
]

create_command = WheelsApp.instance["persistence"].command.create(fact_category: :fact_categories) do |fact_category|
  fact_category.create(fact_type: :fact_types) do |fact_type|
    fact_type.create(:fact_values)
  end
end

create_command.call(facts[0])