How to use the neo4j.NeoService function in neo4j

def init():
    global neo, transaction
    neo = NeoService(NEO_DB, jvm = defaultJVM())
    transaction = neo.transaction

def open(dbpath):
    global dirname, graph, transaction

    if dirname:
        raise RuntimeError("A Neo4j database is already open. Please close it before opening a new one.")

    dirname = dbpath
    graph = NeoService(dbpath, jvm = defaultJVM())
    transaction = graph.transaction

def initAnalyze (self):
        ## create Neo4j DB + index to store analyzed metadata

        self.graphdb = neo4j.NeoService(conf_param["analyze_db_uri"])
        self.uuid_index = self.graphdb.index("uuid.idx", create=True) 
        self.path_index = self.graphdb.index("path.idx", create=True)