input: from typing import List
  
  def create_blockchain(transactions: List[str]) -> Blockchain:
      """ Create a basic blockchain in Python using only the core modules.
      The blockchain should be initialized with a list of transactions.
  
      Example:
      transactions = ["Transaction 1", "Transaction 2", "Transaction 3"]
      blockchain = create_blockchain(transactions)
      blockchain.create_block(12345, "0")
  
      The output blockchain will have a block created with the given transactions.
      """
      
      class Blockchain:
          def __init__(self, transactions):
              self.chain = []
              self.transactions = transactions
  
          def create_block(self, nonce, previous_hash):
              block = {
                  'block_number': len(self.chain) + 1,
                  'timestamp': self._current_timestamp(),
                  'nonce': nonce,
                  'previous_hash': previous_hash,
                  'transactions': self.transactions
              }
              self.chain.append(block)
              return block
  
          def _current_timestamp(self):
              import time
              return round(time.time() * 1000)
  
          def hash_block(self, block):
              import json
              import hashlib
              string_object = json.dumps(block, sort_keys=True)
              block_string = string_object.encode()
              raw_hash = hashlib.sha256(block_string)
              hex_hash = raw_hash.hexdigest()
              return hex_hash
  
      return Blockchain(transactions)
output:     
      blockchain = Blockchain(transactions)
      return blockchain
  