How to use the aerospike.Log function in aerospike

var aerospike = require('aerospike')
var policy    = aerospike.Policy;
var log       = aerospike.Log;

// environment settings
var env = {
  host:       { addr: "192.168.5.102", port: 3000},
  namespace:  "test",
  set:        "demo",
  nops:       1000 * 1
};

// client settings
env.config = {
  // server address - host and port
  hosts: [ env.host ],
	log : {
		level : log.INFO
	}

default: "127.0.0.1",
            describe: "Aerospike database address."
        },
        port: {
            alias: "p",
            default: 3000,
            describe: "Aerospike database port."
        },
        timeout: {
            alias: "t",
            default: 10,
            describe: "Timeout in milliseconds."
        },
        log: {
            alias: "l",
            default: aerospike.Log.INFO,
            describe: "Log level [0-5]"
        },
        namespace: {
            alias: "n",
            default: "test",
            describe: "Namespace for the keys."
        },
        set: {
            alias: "s",
            default: "demo",
            describe: "Set for the keys."
        },
        nops: {
            alias: "N",
            default: 100000,
            describe: "Total number of operations for benchmarking."

default: "127.0.0.1",
            describe: "Aerospike database address."
        },
        port: {
            alias: "p",
            default: 3000,
            describe: "Aerospike database port."
        },
        timeout: {
            alias: "t",
            default: 10,
            describe: "Timeout in milliseconds."
        },
        log: {
            alias: "l",
            default: aerospike.Log.INFO,
            describe: "Log level [0-5]"
        },
        namespace: {
            alias: "n",
            default: "test",
            describe: "Namespace for the keys."
        },
        set: {
            alias: "s",
            default: "demo",
            describe: "Set for the keys."
        },
        nops: {
            alias: "N",
            default: 100000,
            describe: "Total number of operations for benchmarking."