async function main() {
  const lastBlock = await web3.eth.getBlockNumber()
  result = []

  for (let i = lastBlock; i >= lastBlock - 10; i--) {
    let block = await web3.eth.getBlock(i)
    let blockRes = {}
    blockRes.number = i
    blockRes.miner = {}
    blockRes.miner.address = block.miner
    blockRes.miner.balance = await web3.eth.getBalance(block.miner)
    result.push(blockRes)
  }
  console.log(result);
}