code: def mine_blocks(num_blocks: int, chain: MiningChain) -> MiningChain:
      
      if not isinstance(chain, MiningChain):
          raise ValidationError('`mine_block` may only be used on MiningChain instances')
      for _ in range(num_blocks):
          chain.mine_block()
      return chain
docs: Variadic argument version of :func:`~eth.tools.builder.chain.mine_block`