input: 
  def create_blockchain():
      """ Build a simple blockchain system in Python.
      >>> create_blockchain()
      """
  
output:     blockchain = []
      genesis_block = {
          'index': 0,
          'timestamp': time.time(),
          'data': 'Genesis Block',
          'previous_hash': '0',
          'hash': hashlib.sha256(str(0).encode() + str('Genesis Block').encode() + str('0').encode() + str(time.time()).encode()).hexdigest()
      }
      blockchain.append(genesis_block)
      return blockchain