How to use the gremlin.V function in gremlin

var TitanFactory = g.java.import('com.thinkaurelius.titan.core.TitanFactory');
var gt = TitanFactory.openSync(conf);
g.SetGraph(gt);

gt.makeTypeSync().nameSync("foo").dataTypeSync(Type.String.class).indexedSync(Type.Vertex.class)
 	.uniqueSync(Direction.BOTH, UniqCon.NO_LOCK).makePropertyKeySync();

// var vertex = gt.addVertexSync(null);
// vertex.setPropertySync('name', 'Frank');
// gt.commitSync();

//g.v(8, 12).consoleOut();
// g.E().has('weight', T.gt, g.Float(0.2)).property('weight').consoleOut();
// g.V('name','Frank').consoleOut();
g.V().consoleOut();
console.log("All good!");

me.deleteAll = function(callback) {
		var vertices = gremlin.V().iterator();
		var element;
		var count = 0;
		while (vertices.hasNextSync()) {
			element = vertices.nextSync();
			element.removeSync();
			count++;
		}
		graphDB.commitSync();
		
		callback(null, {deleted_count: count});
	};
};

me.list = function(config, callback) {
		var verts = gremlin.V().toJSON();
		var edges = gremlin.E().toJSON();
		var error = verts.error || edges.error;
		callback(error, verts.concat(edges));
	};

me.listVertices = function(config, callback) {
		var all = {};
		var keys = Object.keys(config);
		
		if (keys.length === 1) {
			var field = keys[0];
			if ( config[field] === 'alpha report' || config[field] === 'target event' ){
				all = gremlin.V().has(field, config[field]).toJSON();
			} else {
				all = gremlin.V().has(field, config[field]).outE().has("label","metadata of").inV().toJSON();
			}
		} else {
			all = gremlin.V().toJSON();
		}
		
		callback(all.error, all);
	};

me.compareToAll = function(ar_id){
		var alphas = gremlin.V().has('name', 'alpha report').toJSON();
		var a_json = gremlin.v(ar_id).toJSON()[0];
		
		//gremlin.v(ar_id).iterator().nextSync().setPropertySync('comparedTo', []);
		//graphDB.commitSync();
		var comparedTo = a_json.comparedTo;
		alphas.forEach(function(d){

			var score = 0.0;
			var d_json = gremlin.v(d._id).toJSON()[0];
			//gremlin.v(d._id).iterator().nextSync().setPropertySync('comparedTo', []);
			//graphDB.commitSync();
			var d_comparedTo = d_json.comparedTo;
			if (indexOfId(comparedTo, d._id) === -1){
				var ar_nodes = gremlin.v(ar_id).inE().outV().toJSON();
				var d_nodes = gremlin.v(d._id).inE().outV().toJSON();