I want to add unique objects into list on the basis of property of object.

```
class Employee {
    protected long   employeeId;
    protected String firstName;
    protected String lastName;

    Employee(long employeeId,String firstName,String lastName){
        this.employeeId = employeeId;
        this.firstName = firstName;
        this.lastName = lastName;
    }
}

```

I want to insert object into list on the basis of unique `'employeeId'` and `'firstName'` , combination should be unique while inserting object into list.