docs: def past_trades(self, symbol='btcusd', limit_trades=50, timestamp=0):
          """
          Send a trade history request, return the response.
  
          Arguements:
          symbol -- currency symbol (default 'btcusd')
          limit_trades -- maximum number of trades to return (default 50)
          timestamp -- only return trades after this unix timestamp (default 0)
          """
          request = '/v1/mytrades'
          url = self.base_url + request
          params = {
              'request': request,
              'nonce': self.get_nonce(),
              'symbol': symbol,
              'limit_trades': limit_trades,
              'timestamp': timestamp
          }
  
          return requests.post(url, headers=self.prepare(params))