code: function convertToIcnsTmp(pngSrc, callback) {
    const tempIconDirObj = tmp.dirSync({ unsafeCleanup: true });
    const tempIconDirPath = tempIconDirObj.name;
    convertToIcns(pngSrc, `${tempIconDirPath}/icon.icns`, callback);
  }
docs: Converts the png to a temporary directory which will be cleaned up on process exit
  @param {string} pngSrc
  @param {pngToIcnsCallback} callback