3.5.5.1 Receive GET Request
If the request contains a Range: header, the server MUST follow the rules in section 14.35 of [RFC2616] to validate the byte range(s) being requested and generate an appropriate response message.
If the status of the resulting response is 200 or 206:
The response byte ranges MUST be taken from the matching ranges of DATA_BUFFER.
The response Last-Modified header MUST be set to DATA_TIMESTAMP. For details, see [RFC2616] section 14.29.
If the server supports multiple byte-range requests, the response MUST return the byte ranges in the same order as in the GET request; no merging or reordering of ranges is allowed.