How to disconnect bluetooth device connected to my phone?

Question

I'm trying to build an apk that will disconnect Bluetooth headphones when I press a button. I'm able to get the names and the mac addresses of the connected Bluetooth devices but I don't have a clue what will be the command to disconnect/connect the device. I was looking for something that uses the mac address of the paired device but I can't find anything.

Help will be appreciated.

I have tried this code here

    public void disConnectDevice(String address) {
        BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        BluetoothDevice device = bluetoothAdapter.getRemoteDevice(address);
        BluetoothGatt mBluetoothGatt = device.connectGatt(this, false, gattCallback);
        mBluetoothGatt.disconnect();
    }

    private BluetoothGattCallback gattCallback = new BluetoothGattCallback() {
        @Override
        public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
            super.onConnectionStateChange(gatt, status, newState);
            gatt.close();
        }
    };

but unfortunately, I can't make it work. It does nothing and I don't understand exactly what it is supposed to do.