code: def spendables_for_address(self, address):
          
          spendables = []
          url_append = "?unspentOnly=true&token=%s&includeScript=true" % self.api_key
          url = self.base_url("addrs/%s%s" % (address, url_append))
          result = json.loads(urlopen(url).read().decode("utf8"))
          for txn in result.get("txrefs", []):
              coin_value = txn.get("value")
              script = h2b(txn.get("script"))
              previous_hash = h2b_rev(txn.get("tx_hash"))
              previous_index = txn.get("tx_output_n")
              spendables.append(Tx.Spendable(coin_value, script, previous_hash, previous_index))
          return spendables
docs: Return a list of Spendable objects for the
          given bitcoin address.