anchor.diff:  { pkgs,  stdenv, fetchurl, unzip, elasticsearch-oss, javaPackages, elk6Version }:
  -
  -with pkgs.lib;
   
   let
     esPlugin = a@{
  
positive.code:       url = "https://artifacts.elastic.co/downloads/elasticsearch-plugins/discovery-ec2/discovery-ec2-${elk6Version}.zip";
        sha256 = "1i7ksy69132sr84h51lamgq967yz3a3dw0b54nckxpqwad9pcpj0";
      };
      meta = {
        homepage = https://github.com/elastic/elasticsearch/tree/master/plugins/discovery-ec2;
        description = "The EC2 discovery plugin uses the AWS API for unicast discovery.";
        license = licenses.asl20;
  
negative.code:       url = "mirror://maven/com/floragunn/search-guard-6/${version}/search-guard-6-${version}.zip";
        sha256 = "1r71h4h9bmxak1mq5gpm19xq5ji1gry1kp3sjmm8azy4ykdqdncx";
      };
      meta = with stdenv.lib; {
        homepage = https://github.com/floragunncom/search-guard;
        description = "Plugin to fetch data from JDBC sources for indexing into Elasticsearch";
        license = licenses.asl20;
  