fn process_hash<B, C, JS>(
    hash: BlockHash,
    multisignature: SignatureSet<Signature>,
    justifications_for_chain: &mut JS,
    justification_translator: &JustificationTranslator,
    client: &Arc<C>
) -> Result<(), ()>
where B: Block<Hash = BlockHash>, B::Header: Header<Number = BlockNumber>, C: HeaderBackend<B> + Send + Sync + 'static, JS: JustificationSubmissions<Justification> + Send + Sync + Clone,