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: test.rs
    path of file: ./repos/ckb/rpc/src/module
    
    the code of the file until where you have to start completion: use crate::error::RPCError;
use async_trait::async_trait;
use ckb_chain::chain::ChainController;
use ckb_dao::DaoCalculator;
use ckb_jsonrpc_types::{Block, BlockTemplate, Byte32, EpochNumberWithFraction, Transaction};
use ckb_l
    
    fn process_and_announce_block(&self, block: packed::Block) -> Result<H256> {
        let block_view = Arc::new(block.into_view());
        let content = packed::CompactBlock::build_from_block(&block_view, &HashSet::new());
        let message = packed::RelayMessage::new_builder().set(content).build();

        // insert block to chain
        self.chain
            .process_block(Arc::clone(&block_view))
            .map_err(|err| RPCError::custom(RPCError::CKBInternalError, err.to_string()))?;

        // announce new block
        if let Err(err) = self
            .network_controller
            .quick_broadcast(SupportProtocols::RelayV2.protocol_id(), message.as_bytes())
        {
            error!("Broadcast new block failed: {:?}", err);
        }

        Ok(block_view.header().hash().unpack())
    }