parameter missing example: op_test_vs_pydensecrf

[JulienFleuret]

Hello

When I try to execute the python code from the file "op_test_vs_pydensecrf" I receive an error because an argument in not set in the call of the method:

    q = tf.foldl(lambda prev, it: meanfield_iteration(prev, unaries, 
                 tf.range(0, num_iters), 
                 initializer=q_init,
                 parallel_iterations=32)  )

in the function meanfield_op.