code: def _member_data_key(self, leaderboard_name):
          '''
          Key for retrieving optional member data.
  
          @param leaderboard_name [String] Name of the leaderboard.
          @return a key in the form of +leaderboard_name:member_data+
          '''
          if self.global_member_data is False:
              return '%s:%s' % (leaderboard_name, self.member_data_namespace)
          else:
              return self.member_data_namespacf _member_data_key(self, leaderboard_name):
          '''
          Key for retrieving optional member data.
  
          @param leaderboard_name [String] Name of the leaderboard.
          @return a key in the form of +leaderboard_name:member_data+
          '''
          if self.global_member_data is False:
              return '%s:%s' % (leaderboard_name, self.member_data_namespace)
          else:
              return self.member_data_namespace
docs: Key for retrieving optional member data.
  
          @param leaderboard_name [String] Name of the leaderboard.
          @return a key in the form of +leaderboard_name:member_data+