code: def user_transactions(self, offset=0, limit=100, descending=True,
                            base=None, quote=None):
          
          data = {
              'offset': offset,
              'limit': limit,
              'sort': 'desc' if descending else 'asc',
          }
          url = self._construct_url("user_transactions/", base, quote)
          return self._post(url, data=data, return_json=True, version=2)
docs: Returns descending list of transactions. Every transaction (dictionary)
          contains::
  
              {u'usd': u'-39.25',
               u'datetime': u'2013-03-26 18:49:13',
               u'fee': u'0.20',
               u'btc': u'0.50000000',
               u'type': 2,
               u'id': 213642}
  
          Instead of the keys btc and usd, it can contain other currency codes