code: def tx_sign_all_unsigned_inputs(privkey_info, prev_outputs, unsigned_tx_hex, blockchain='bitcoin', **blockchain_opts):
      
      if blockchain == 'bitcoin':
          return btc_tx_sign_all_unsigned_inputs(privkey_info, prev_outputs, unsigned_tx_hex, **blockchain_opts)
      else:
          raise ValueError('Unknown blockchain "{}"'.format(blockchain))
docs: Sign all unsigned inputs to a given transaction with the given private key.  Also, pass in the list of previous outputs to the transaction so they
      can be paired with the right input (i.e. prev_outputs is a list of tx outputs that are in 1-to-1 correspondance with the inputs in the serialized tx)
      
      Different blockchains can require additional fields; pass thse in **blockchain_opts.
  
      Return the signed transaction on success
      Raise on error