if you use RadioGroup in android, you can't put RadioButtons anywhere you want except the exact child of your RadioGroup with no depth of hierarchy. so if you want to put your RadioButtons in a LinearLayout or manage it in a grid, buttons don't act like their belongs to the group (they will stay checked if the user check another RadioButton in the group)
import the file and simply add this line of code to declare a RadioGroup:
RadioGroupCheckListener.makeGroup(radioButton1, radioButton2, radioButton3, radioButton4);
or use this function using their ids instead of using their objects (this is the activity that contains radio buttons)
RadioGroupCheckListener.makeGroup(this, R.id.radioButton1_id, R.id.radioButton2_id, R.id.radioButton3_id, R.id.radioButton4_id);