input: def create_basic_blockchain():
      """Create a basic blockchain class in Python using only the core modules. The blockchain should have methods to initialize the chain, create a new block, and hash a block.
      Example:
      b = create_basic_blockchain()
      b.create_block(nonce=1, previous_hash='0')
      b.create_block(nonce=2, previous_hash='abc')
      >>> b.chain[-1]['nonce']
      2
      >>> b.hash_block(b.chain[0])
      'hash_of_block_0'
      """
output:     class Blockchain:
          def __init__(self):
              self.chain = []
          
          def create_block(self, nonce, previous_hash):
              block = {
                  'nonce': nonce,
                  'previous_hash': previous_hash
              }
              self.chain.append(block)
          
          def hash_block(self, block):
              import hashlib
              block_string = str(block).encode()
              return hashlib.sha256(block_string).hexdigest()
      
      return Blockchain()