code: def _auth(self):
          
          ts = datetime.datetime.now().strftime("%Y-%m-%d%H:%M:%S")
          hash_string = hashlib.md5("%s%s%s" % (ts, self.private_key, self.public_key)).hexdigest()
          return "ts=%s&apikey=%s&hash=%s" % (ts, self.public_key, hash_string)
docs: Creates hash from api keys and returns all required parametsrs
          
          :returns:  str -- URL encoded query parameters containing "ts", "apikey", and "hash"