public GraftContext execute(Changeset changeset) {
Repository repo = getRepository();
repo.lock();
HgInputStream stream = launchStream(changeset.getNode());
try {
if (stream.match("grafting revision ".getBytes())) {
int rev = stream.revisionUpTo('\n');
GraftContext ctx = new GraftContext(this, rev);
if (!stream.isEof()) {
ctx.processStream(stream, true);
}