public class Login {
    private String username;
    private String password;
    public void setUp(){
        // navigate to the login page
    }
    public void tearDown(){
        // logout of the system
    }
    public void setUsername(String username){
	    this.username = username;
    }
    public void setPassword(String password){
        this.password = password;
    }
    public boolean valid(){
       // check if the user and pass is valid.
    }
}