fn get_message_for_next_step_proof<'a, AppState>(
messages_for_next_step_proof: &PicklesProofProofsVerified2ReprStableV2MessagesForNextStepProof,
commitments: &'a PlonkVerificationKeyEvals<Fp>,
app_state: &'a AppState,
) -> Result<MessagesForNextStepProof<'a, AppState>, InvalidBigInt>where
AppState: ToFieldElements<Fp>,