anchor.diff:      name = "${pname}-${version}";
       format = "wheel";
   
  -    src = fetchpypi {
  +    src = fetchPypi {
         inherit pname version format;
         sha256 = "0a0685962ee5ac303f470acbb659f0f97aef5b9deb6b85d059691c706ef6e45e";
       };
  
positive.code:     #  ${python.interpreter} -m unittest discover
      #'';
      format = "wheel";
      src = fetchpypi {
        inherit pname version format;
        sha256 = "f16b2cb3b03e1ada4fb0200b265a4446f92f3ba4b9d88ace34f51c54ab6d294e";
      };
  
negative.code:     pname = "pandocfilters";
      name = pname + "-${version}";
  
      src = fetchPypi{
        inherit pname version;
        sha256 = "ec8bcd100d081db092c57f93462b1861bcfa1286ef126f34da5cb1d969538acd";
      };
  