anchor.diff:  , stdenv
   , buildPythonPackage
   , python
  -, isPy3k
  +, pythonOlder
   , arrow-cpp
   , cffi
   , cloudpickle
  
positive.code:     ulimit -n 1024
    '';
  
    pythonImportsCheck = [ "pyarrow" ] ++ map (module: "pyarrow.${module}") ([
      "compute"
      "csv"
      "dataset"
  
negative.code:     "hdfs"
      "json"
      "parquet"
    ] ++ lib.optionals (!stdenv.isDarwin) [
      "plasma"
    ]);
  
    meta = with lib; {
      description = "A cross-language development platform for in-memory data";
  