anchor.diff:  { stdenv
   , buildPythonPackage
   , fetchPypi
  +, configparser
  +, pyparsing
   , pytest
   , future
  +, openpyxl
  +, wrapt
   }:
   
   buildPythonPackage rec {
  
positive.code:     description = "Provides tools for working with pair and embedded atom method potential models including tabulation routines for DL_POLY and LAMMPS";
      license = licenses.mit;
      maintainers = [ maintainers.costrouc ];
    };
  }
  
negative.code:   };
  
    checkInputs = [ pytest ];
    propagatedBuildInputs = [
      configparser
      future
      openpyxl
      pyparsing
      wrapt
    ];
  
    postPatch = ''
      substituteInPlace setup.py \
        --replace "wrapt==1.11.2" "wrapt~=1.11"
    '';
  
    # tests are not included with release
    doCheck = false;
  