# File lib/hiera/backend.rb, line 153
            def lookup(key, default, scope, order_override, resolution_type)
                @backends ||= {}
                answer = nil

                Config[:backends].each do |backend|
                    if constants.include?("#{backend.capitalize}_backend")
                        @backends[backend] ||= Backend.const_get("#{backend.capitalize}_backend").new
                        answer = @backends[backend].lookup(key, scope, order_override, resolution_type)

                        break if answer
                    end
                end

                answer = resolve_answer(answer, resolution_type)
                answer = parse_string(default, scope) if answer.nil?

                return default if answer == empty_answer(resolution_type)
                return answer
            end