**Script output**::

  Training 1-slack dual structural SVM
  new constraint too weak.
  new constraint too weak.
  no additional constraints
  Switching to ad3bb inference
  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=ad3bb, tol=0.001, verbose=0)
  Iterations: 243
  Objective: 505.245003
  Gap: 0.018169

