# File lib/moneta/adapters/lmdb.rb, line 20
      def initialize(options)
        db = options.delete(:db)
        @backend = options.delete(:backend) ||
          begin
            raise ArgumentError, 'Option :dir is required' unless dir = options.delete(:dir)
            FileUtils.mkpath(dir)
            ::LMDB.new(dir, options)
          end

        @db = @backend.database(db, :create => true)
      end