anchor.diff:      substituteInPlace requirements.txt \
         --replace "matplotlib~=3.0" "matplotlib" \
         --replace "networkx~=2.4" "networkx" \
  -      --replace "numpy~=1.16" "numpy" \
  -      --replace "requests~=2.18" "requests"
  +      --replace "numpy~=1.16" "numpy"
     '';
   
     propagatedBuildInputs = [
  
positive.code:     owner = "quantumlib";
      repo = "cirq";
      rev = "v${version}";
      hash = "sha256-JaKTGnkYhzIFb35SGaho8DRupoT0JFYKA5+rJEq4oXw=";
    };
  
    sourceRoot = "source/${pname}";
  
negative.code: , freezegun
  , pytest-asyncio
  }:
  
  buildPythonPackage rec {
    pname = "cirq-core";
    version = "0.12.0";
  
    disabled = pythonOlder "3.6";
  
  