def connect(self): 
        try:
            self.connection = pymongo.Connection(self.host, self.port)
            self.db = self.connection[self.name]
        except AutoReconnect:
            raise DatabaseException("It's not possible connect to the database")
def get_clusters(self):
        """!
        @return (list) Allocated clusters where each cluster is represented by list of indexes of points from dataset,
                        for example, two cluster may have following representation [[0, 1, 4], [2, 3, 5, 6]].