shadows/framework/src/main/java/org/robolectric/shadows/ShadowBluetoothDevice.java
public void simulateGattConnectionChange(int status, int newState) {
    for (BluetoothGatt bluetoothGatt : bluetoothGatts) {
      ShadowBluetoothGatt shadowBluetoothGatt = Shadow.extract(bluetoothGatt);
      BluetoothGattCallback gattCallback = shadowBluetoothGatt.getGattCallback();
      gattCallback.onConnectionStateChange(bluetoothGatt, status, newState);
    }
  }
public void simulateGattConnectionChange(int status, int newState) {
    for (BluetoothGatt bluetoothGatt : bluetoothGatts) {
      ShadowBluetoothGatt shadowBluetoothGatt = Shadow.extract(bluetoothGatt);
      BluetoothGattCallback gattCallback = shadowBluetoothGatt.getGattCallback();
      gattCallback.onConnectionStateChange(bluetoothGatt, status, newState);
    }
  }
Causes {@link BluetoothGattCallback#onConnectionStateChange to be called for every GATT client.
@param status Status of the GATT operation
@param newState The new state of the GATT profile