code: def add(self, pkgs):
          
          blacklist = self.get_black()
          pkgs = set(pkgs)
          print("\nAdd packages in the blacklist:\n")
          with open(self.blackfile, "a") as black_conf:
              for pkg in pkgs:
                  if pkg not in blacklist:
                      print("{0}{1}{2}".format(self.meta.color["GREEN"], pkg,
                                               self.meta.color["ENDC"]))
                      black_conf.write(pkg + "\n")
                      self.quit = True
              black_conf.close()
          if self.quit:
              print("")
docs: Add blacklist packages if not exist