input: 
  def create_basic_blockchain() -> str:
      """Create a basic blockchain system in Python. It should include a class for each
      block and a class for the blockchain. The blockchain class should have methods
      to add blocks and to get the entire chain in JSON format.
      >>> create_basic_blockchain()[-40:]
      '           "data": "Sample Data",\\n'
      """
  
output:     
      class Block:
          def __init__(self, index, previous_hash, data, timestamp):
              self.index = index
              self.previous_hash = previous_hash
              self.data = data
              self.timestamp = timestamp
              self.hash = self.calculate_hash()
  
          def calculate_hash(self):
              block_string = f"{self.index}{self.previous_hash}{self.data}{self.timestamp}"
              return hashlib.sha256(block_string.encode()).hexdigest()
  
      class Blockchain:
          def __init__(self):
              self.chain = [self.create_genesis_block()]
  
          def create_genesis_block(self):
              return Block(0, "0", "Genesis Block", time.time())
  
          def get_latest_block(self):
              return self.chain[-1]
  
          def add_block(self, data):
              latest_block = self.get_latest_block()
              new_block = Block(latest_block.index + 1, latest_block.hash, data, time.time())
              self.chain.append(new_block)
  
          def get_chain_json(self):
              chain_data = []
              for block in self.chain:
                  chain_data.append({
                      "index": block.index,
                      "previous_hash": block.previous_hash,
                      "data": block.data,
                      "timestamp": block.timestamp,
                      "hash": block.hash
                  })
              return json.dumps(chain_data, indent=4)
  
      blockchain = Blockchain()
      blockchain.add_block("Sample Data")
      return blockchain.get_chain_json()
  