def insertDomain(self, domain, indegree=0, outdegree=0):
		'''增加一个域名'''
		cur = self.conn.cursor()
		cur.execute("INSERT INTO Domains VALUES (NULL,?,?,?)", (domain, indegree, outdegree))
		# 写入到文件中
		self.conn.commit()
def notify(self, means, covariances, clusters):
        """!
        @brief This method is used by the algorithm to notify observer about changes where the algorithm
                should provide new values: means, covariances and allocated clusters.