anchor.diff:            "fs.defaultFS" = "hdfs://localhost";
           }
         '';
  -      description = "Hadoop core-site.xml definition";
  +      description = ''
  +        Hadoop core-site.xml definition
  +        <link xlink:href="https://hadoop.apache.org/docs/current/hadoop-project-dist/hadoop-common/core-default.xml"/>
  +      '';
       };
   
       hdfsSite = mkOption {
  
positive.code:           "dfs.nameservices" = "namenode1";
          }
        '';
        description = "Hadoop hdfs-site.xml definition";
      };
  
      mapredSite = mkOption {
  
negative.code:           "yarn.resourcemanager.hostname" = "''${config.networking.hostName}";
          }
        '';
        description = ''
          Hadoop yarn-site.xml definition
          <link xlink:href="https://hadoop.apache.org/docs/current/hadoop-yarn/hadoop-yarn-common/yarn-default.xml"/>
        '';
      };
  
      httpfsSite = mkOption {
  