**Script output**::

  Training 1-slack dual structural SVM
  new constraint too weak.
  new constraint too weak.
  new constraint too weak.
  new constraint too weak.
  no additional constraints
  OneSlackSSVM(C=1, break_on_bad=False, cache_tol=auto, check_constraints=True,
         inactive_threshold=1e-10, inactive_window=50, inference_cache=100,
         logger=None, max_iter=1000,
         model=DirectionalGridCRF(n_states: 3, inference_method: qpbo),
         n_jobs=-1, positive_constraint=None, show_loss_every=10,
         switch_to=None, tol=0.1, verbose=0)
  Iterations: 192
  Objective: 502.445839
  Gap: -19.767398

