# File lib/mongo/server_selector/selectable.rb, line 228
      def candidates(cluster)
        if cluster.single?
          cluster.servers.each { |server| validate_max_staleness_support!(server) }
        elsif cluster.sharded?
          near_servers(cluster.servers).each { |server| validate_max_staleness_support!(server) }
        else
          validate_max_staleness_value!(cluster) unless cluster.unknown?
          select(cluster.servers)
        end
      end