anchor.diff: -{ lib, buildPythonPackage, fetchPypi,
  -  pytest, requests, requests_oauthlib, six
  +{ lib, buildPythonPackage, pytest, requests, requests_oauthlib, six
  +, fetchFromGitHub, responses, stdenv
   }:
   
   buildPythonPackage rec {
  
positive.code:     sed -i "s/requests_oauthlib~=0.6.1/requests_oauthlib >=0.6.1/" setup.py
    '';
  
    # ERROR: file not found: tests
    doCheck = false; 
  
    checkPhase = ''
      py.test tests
    '';
  
  }
  
negative.code:   version = "0.7.0";
    name = "${pname}-${version}";
  
    src = fetchFromGitHub {
      owner = "asana";
      repo = "python-asana";
      rev = "v${version}";
      sha256 = "0786y3wxqxxhsb0kkpx4bfzif3dhvv3dmm6vnq58iyj94862kpxf";
    };
  
    checkInputs = [ pytest responses ];
    propagatedBuildInputs = [ requests requests_oauthlib six ];
  
    patchPhase = ''
  