anchor.diff:      meta = {
         description = "Determine minimum Perl version of POD directives";
         homepage = "https://user42.tuxfamily.org/pod-minimumversion/index.html";
  -      license = with lib.licenses; [ free ];
  +      license = with lib.licenses; [ gpl3Plus ];
         mainProgram = "pod-minimumversion";
       };
     };
  
positive.code:     propagatedBuildInputs = [ NumberFormat ];
      meta = {
        description = "A collection of very basic statistics modules";
        license = with lib.licenses; [ free ];
      };
    };
  
  
negative.code:     meta = {
        description = "Module to align text";
        homepage = "https://metacpan.org/release/Text-Aligner";
        license = with lib.licenses; [ isc ];
      };
    };
  
  