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 delete_snapshot_metadata_item(self, snapshot_id, id):
        """Delete metadata item for the snapshot."""
        url = "snapshots/%s/metadata/%s" % (str(snapshot_id), str(id))
        resp, body = self.delete(url)
        return resp, body