message: [accumulator]  format code
diff: @@ -76,10 +76,7 @@ where
  let head_block_hash = chain_info.get_head();
  let head = storage
  .get_block_by_hash(head_block_hash)?
  - .ok_or(format_err!(
  - "Can not find block by hash {}",
  - head_block_hash
  - ))?;
  + .ok_or_else(|| format_err!("Can not find block by hash {}", head_block_hash))?;
  let block_info = match storage.clone().get_block_info(head_block_hash) {
  Ok(Some(block_info_1)) => block_info_1,
  Err(e) => {
  