* {@link #sequence} ���� {@link SubMessage} �����o���܂��B
* {@link SubMessage} �� {@link Sequence#getTracks()}[0] �̐擪�ɂ���̂��d�l
*/
public HeaderChunk(Sequence sequence) {
//
Track track = sequence.getTracks()[0];
for (int j = 0; j < track.size(); j++) {
MfiEvent event = track.get(j);
MfiMessage message = event.getMessage();
if (message instanceof SubMessage) {
SubMessage subChunk = (SubMessage) message;
//Debug.println(infoMessage);
subChunks.put(subChunk.getSubType(), subChunk);