input: 
  def create_blockchain(data):
      """Create a basic blockchain system in Python and add a block to it. 
      The function will return the entire blockchain in JSON format.
  
      >>> create_blockchain({'timestamp': '2023-10-01 12:00:00', 'data': 'First block'})
      '[{
        "index": 0,
        "timestamp": "2023-10-01 12:00:00",
        "data": "First block",
        "previous_hash": null,
        "hash": "d2a9e0b98b3f8f213640e717ceb1342d01b4a1fb2fd8149129afc4b4e68f01f8"
      }]'
      """
      blockchain = Blockchain()
      blockchain.add_block(data)
      return blockchain.get_chain()
  
output:     class Blockchain:
          def __init__(self):
              self.chain = []
              self.create_genesis_block()
          
          def create_genesis_block(self):
              genesis_block = {
                  "index": 0,
                  "timestamp": "2023-10-01 12:00:00",
                  "data": "Genesis Block",
                  "previous_hash": None,
                  "hash": "d2a9e0b98b3f8f213640e717ceb1342d01b4a1fb2fd8149129afc4b4e68f01f8"
              }
              self.chain.append(genesis_block)
          
          def add_block(self, data):
              previous_block = self.chain[-1]
              new_block = {
                  "index": len(self.chain),
                  "timestamp": data['timestamp'],
                  "data": data['data'],
                  "previous_hash": previous_block['hash'],
                  "hash": self.calculate_hash(data['timestamp'], data['data'], previous_block['hash'])
              }
              self.chain.append(new_block)
          
          def calculate_hash(self, timestamp, data, previous_hash):
              import hashlib
              value = f"{timestamp}{data}{previous_hash}"
              return hashlib.sha256(value.encode()).hexdigest()
          
          def get_chain(self):
              import json
              return json.dumps(self.chain, indent=4)