docs: def shuffle(self, overwrite=False):
          """
          This method creates new shuffled file.
          """
  
          if overwrite:
              shuffled = self.path
          else:
              shuffled = FileAPI.add_ext_name(self.path, "_shuffled")
  
          lines = open(self.path).readlines()
          random.shuffle(lines)
          open(shuffled, "w").writelines(lines)
          self.path = shuffled