code: def parse(cls, fptr, offset, length):
          
          num_bytes = offset + length - fptr.tell()
          read_buffer = fptr.read(num_bytes)
          data = struct.unpack_from('>BBBB', read_buffer)
          version = data[0]
          flag = data[1:4]
  
          url = read_buffer[4:].decode('utf-8').rstrip(chr(0))
          return cls(version, flag, url, length=length, offset=offset)
docs: Parse data entry URL box.
  
          Parameters
          ----------
          fptr : file
              Open file object.
          offset : int
              Start position of box in bytes.
          length : int
              Length of the box in bytes.
  
          Returns
          -------
          DataEntryURLbox
              Instance of the current data entry URL box.