docs: def _overwrite(self, n):
          """Overwrite old file with new and keep file with suffix .old
          """
          if os.path.isfile(n[:-4]):
              shutil.copy2(n[:-4], n[:-4] + ".old")
              print("Old file {0} saved as {1}.old".format(
                  n[:-4].split("/")[-1], n[:-4].split("/")[-1]))
          if os.path.isfile(n):
              shutil.move(n, n[:-4])
              print("New file {0} overwrite as {1}".format(
                  n.split("/")[-1], n[:-4].split("/")[-1]))