JS API: get and set customProps

//Get props          
console.log(user.getName(),user.getCustomProps());            
//Set props          
var props = [{name: "John", value: "Doe"}, {name: "Foo", value: "Bar"}];        
wialon.core.Remote.getInstance().startBatch();
for(var i=0;i <props.length; i++)
    user.updateCustomProperty(props[i].name, props[i].value);//Update custom property, require ACL bit wialon.item.Item.accessFlag.editOther over item        
wialon.core.Remote.getInstance().finishBatch(function() {              
    console.log(user.getName(),user.getCustomProps());
});

You can get user in 3 ways:
1) by id
var user =  wialon.core.Session.getInstance().getItem(id);   
console.log(user);

2) by name        
var spec = {itemsType: "user", propName: "sys_name", propValueMask: "name", sortType: ""};
wialon.core.Session.getInstance().searchItems(spec, 2, wialon.item.Item.dataFlag.base, 0, 0, qx.lang.Function.bind(function(code, result) {            
    if (code || !result || typeof result.items == "undefined" || !result.items.length)
        return;
    console.log(result.items[0]);
}, this));

3) get current user
var user = wialon.core.Session.getInstance().getCurrUser();
console.log(user);

note for 1) and 2): you can only get those users that you can access according access rights

You can't write like this: wialon.item.Item.getCustomProps() because THIS METHOD ISN"T STATIC