def METHOD_NAME():
    context, config = make_context()
    request = make_request()
    request.fill(config.account.address, b"", FILL_ID, TIMESTAMP)
    context.requests.add(request.id, request)
    assert request.fill_id is not None
    claim = make_claim_unchallenged(
        request=request,
        claimer=config.account.address,
        fill_id=request.fill_id,
        stay_in_started_state=True,
    )
    context.claims.add(claim.id, claim)
    tx_hash = make_tx_hash()
    event = FillInvalidated(
        event_chain_id=request.target_chain_id,
        event_address=to_checksum_address(ADDRESS_ZERO),
        tx_hash=tx_hash,
        request_id=request.id,
        fill_id=request.fill_id,
        block_number=BLOCK_NUMBER,
    )
    assert process_event(event, context) == (True, None)
    # Check that the event changes the claim state
    assert claim.claimer_winning.is_active
    assert claim.invalidation_tx == tx_hash