<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_current_round(self, tournament=1):
 """Get number of the current active round. Args: tournament (int):
 ID of the tournament (optional, defaults to 1) Returns: int: number of the current active round Example: 104 """

        # zero is an alias for the current round!
        query = '''
            query($tournament: Int!) {
              rounds(tournament: $tournament
                     number: 0) {
                number
              }
            }
        '''
        arguments = {'tournament': tournament}
        data = self.raw_query(query, arguments)['data']['rounds'][0]
        if data is None:
            return None
        round_num = data["number"]
        return round_num