Assigne false becomes always nil

test.rb

require 'lotus/model'
require 'sequel'
require 'sqlite3'
require 'minitest/autorun'
require 'pp'

class Item
  include Lotus::Entity

  self.attributes = :sold
end

class ItemRepository
  include Lotus::Repository
end

describe "taste field is not mapped" do

  before(:each) do

    uri = "sqlite:///tmp/test.db"

    Lotus::Model.configure do

      adapter type: :sql, uri: uri, default: true

      mapping do
        collection :items do
          entity Item

          attribute :id,             Integer
          attribute :sold,           Boolean
        end
      end
    end

    database = Sequel.connect(uri)

    database.drop_table? :items

    database.create_table :items do
      primary_key   :id
      Boolean     :sold
    end

    Lotus::Model.load!

  end

  it 'setting sold field to false is nil' do
    ItemRepository.create(Item.new(sold: false))

    ItemRepository.first.sold.must_be_nil
  end

  it 'but setting to true works' do
    ItemRepository.create(Item.new(sold: true))

    ItemRepository.first.sold.must_equal true
  end
end