model->get_release_seq_heads(this, &release_heads);
for (unsigned int i = 0; i < release_heads.size(); i++)
synchronize_with(release_heads[i]);
model->get_release_seq_heads(this, &release_heads);
for (unsigned int i = 0; i < release_heads.size(); i++)
synchronize_with(release_heads[i]);