anchor.diff:        dns_sd_configs = mkOption {
           type = types.listOf promTypes.dns_sd_config;
           default = [];
  -        apply = x: map _filter x;
           description = ''
             List of DNS service discovery configurations.
           '';
  
positive.code:       ec2_sd_configs = mkOption {
          type = types.listOf promTypes.ec2_sd_config;
          default = [];
          apply = x: map _filter x;
          description = ''
            List of EC2 service discovery configurations.
          '';
  
negative.code:       static_configs = mkOption {
          type = types.listOf promTypes.static_config;
          default = [];
          description = ''
            List of labeled target groups for this job.
          '';
  