You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: mod.rs
    path of file: ./repos/polkadot/node/network/collator-protocol/src/collator_side/tests
    
    the code of the file until where you have to start completion: // Copyright (C) Parity Technologies (UK) Ltd.
// This file is part of Polkadot.

// Polkadot is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// Polkadot is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.

use super::*;

use std::{co
    
fn collate_on_two_different_relay_chain_blocks() {
	let mut test_state = TestState::default();
	let local_peer_id = test_state.local_peer_id;
	let collator_pair = test_state.collator_pair.clone();

	test_harness(
		local_peer_id,
		collator_pair,
		ReputationAggregator::new(|_| true),
		|mut test_harness| async move {
			let virtual_overseer = &mut test_harness.virtual_overseer;

			let peer = test_state.current_group_validator_peer_ids()[0];
			let validator_id = test_state.current_group_validator_authority_ids()[0].clone();

			let peer2 = test_state.current_group_validator_peer_ids()[1];
			let validator_id2 = test_state.current_group_validator_authority_ids()[1].clone();

			setup_system(virtual_overseer, &test_state).await;

			// A validator connected to us
			connect_peer(virtual_overseer, peer, CollationVersion::V1, Some(validator_id)).await;

			// Connect the second validator
			connect_peer(virtual_overseer, peer2, CollationVersion::V1, Some(validator_id2)).await;

			expect_declare_msg(virtual_overseer, &test_state, &peer).await;
			expect_declare_msg(virtual_overseer, &test_state, &peer2).await;

			distribute_collation(virtual_overseer, &test_state, test_state.relay_parent, true)
				.await;

			let old_relay_parent = test_state.relay_parent;

			// Advance to a new round, while informing the subsystem that the old and the new relay
			// parent are active.
			test_state.advance_to_new_round(virtual_overseer, true).await;

			distribute_collation(virtual_overseer, &test_state, test_state.relay_parent, true)
				.await;

			send_peer_view_change(virtual_overseer, &peer, vec![old_relay_parent]).await;
			expect_advertise_collation_msg(virtual_overseer, &peer, old_relay_parent, None).await;

			send_peer_view_change(virtual_overseer, &peer2, vec![test_state.relay_parent]).await;

			expect_advertise_collation_msg(virtual_overseer, &peer2, test_state.relay_parent, None)
				.await;
			test_harness
		},
	)
}