docs: def tx_verify( cls, verified_block_txids, tx ):
          """
          Given the block's verified block txids, verify that a transaction is legit.
          @tx must be a dict with the following fields:
          * locktime: int
          * version: int
          * vin: list of dicts with:
             * vout: int,
             * hash: hex str
             * sequence: int (optional)
             * scriptSig: dict with:
                * hex: hex str
          * vout: list of dicts with:
             * value: float
             * scriptPubKey: dict with:
                * hex: hex str
          """
          tx_hash = cls.tx_hash( tx )
          return tx_hash in verified_block_txids