code: def data(offset, bytes):
          
          assert 0 <= offset < 65536
          assert 0 < len(bytes) < 256
          b = [len(bytes), (offset>>8)&0x0FF, offset&0x0FF, 0x00] + bytes
          return Record._from_bytes(b)
docs: Return Data record. This constructs the full record, including
          the length information, the record type (0x00), the
          checksum, and the offset.
  
          @param  offset  load offset of first byte.
          @param  bytes   list of byte values to pack into record.
  
          @return         String representation of one HEX record