code: def set_value(self, key, value):
          
          file_cache = self.read_file()
          if file_cache:
              file_cache[key] = value
          else:
              file_cache = {}
          file_cache[key] = value
          self.update_file(file_cache)
docs: Set key value to the file.
  
          The fuction will be make the key and value to dictinary formate.
          If its exist then it will update the current new key value to
          the file.
          Arg:
          key : cache key
          value : cache value