text: 
  let Block = require('./block')
  let Blockchain = require('./blockchain')
  let Transaction = require('./transaction')
  
  let transaction = new Transaction('Mary','Jerry',100)
  console.log('\nlog 01', transaction)
  
  let genesisBlock = new Block()
  console.log('\nlog 02', genesisBlock)
  let blockchain = new Blockchain(genesisBlock)
  console.log('\nlog 03', blockchain)
  
  let block = blockchain.getNextBlock([transaction])
  console.log('\nlog 04', block)
  blockchain.addBlock(block)
  console.log('\nlog 05', blockchain)
  
  let anotherTransaction = new Transaction("Azam","Jerry",10)
  console.log('\nlog 06', anotherTransaction)
  let block1 = blockchain.getNextBlock([anotherTransaction,transaction])
  console.log('\nlog 07', block1)
  blockchain.addBlock(block1)
  console.log('\nlog 08', blockchain)