Using shape_invariant argument

Hello,

I'm facing a issue when running ignnition with the aggregation type parameter "ordered" (it works fine with min, max, etc.). I'm receiving this message:

**ValueError: Input tensor 'ignnition_model/states_creation/actions/build_state0/concat_1:0' enters the loop with shape (1, 32), but has shape (None, 32) after one iteration. To allow the shape to vary across iterations, use the `shape_invariants` argument of tf.while_loop to specify a less-specific shape.**

Where in the can I change this parameter?
Thanks!