message: [accumulator] remove  unwrap
diff: @@ -53,32 +53,32 @@ impl BlockExecutor {
  }
  state_root = chain_state
  .commit()
  - .map_err(|_err| BlockExecutorError::BlockChainStateCommitErr)
  - .unwrap();
  + .map_err(|_err| BlockExecutorError::BlockChainStateCommitErr)?;
  }
  let (accumulator_root, first_leaf_idx) = accumulator
  .append(&transaction_hash)
  - .map_err(|_err| BlockExecutorError::BlockAccumulatorAppendErr)
  - .unwrap();
  + .map_err(|_err| BlockExecutorError::BlockAccumulatorAppendErr)?;
  // transaction verify proof
  if !is_preview {
  transaction_hash.iter().enumerate().for_each(|(i, hash)| {
  let leaf_index = first_leaf_idx + i as u64;
  - let proof = accumulator
  + if let Some(proof) = accumulator
  .get_proof(leaf_index)
  - .map_err(|_err| BlockExecutorError::BlockAccumulatorGetProofErr)
  - .unwrap()
  - .unwrap();
  + .map_err(|_err| BlockExecutorError::BlockAccumulatorGetProofErr)?
  + {
  proof
  .verify(accumulator_root, *hash, leaf_index)
  .map_err(|_err| {
  - BlockExecutorError::BlockAccumulatorVerifyErr(accumulator_root, leaf_index)
  - })
  - .unwrap();
  + BlockExecutorError::BlockAccumulatorVerifyErr(
  + accumulator_root,
  + leaf_index,
  + )
  + })?;
  + }
  });
  - accumulator.flush().unwrap();
  + accumulator.flush()?;
  chain_state
  .flush()
  .map_err(|_err| BlockExecutorError::BlockChainStateFlushErr)?;
  