Android : Hide another app luncher icon

I'm new to android programming. I'm developing an app with a button that when that button pressed i want to hide WhatsApp luncher icon. how can i do that? i know that i should use PakageManager but i have no idea how to use it. please help.after a long search i found this code but i have no idea how to use it:

ComponentName componentToDisable =new ComponentName("target package name",
                      "target launcher activity");
getPackageManager().setComponentEnabledSetting(
                      componentToDisable,
                      PackageManager.COMPONENT_ENABLED_STATE_DISABLED,
                      PackageManager.DONT_KILL_APP);