MapClientImpl.java

// Now we can have multiple implementations of MapClient interface.

class GoogleMapsClientImpl implements MapsClient {
  private GoogleMapsClient googleMapsClient;
  
  public GoogleMapsClientImpl(GoogleMapsClient client) {
    googleMapsClient = client;
  }
  
  @Override
  public boolean isVerified(String address) {
    return googleMapsClient.verifyAddress(address).result == Result.SUCCESS;
  }
}

class BingMapsClientImpl implements MapsClient {
  private BingMapsClient bingMapsClient;
  public BingMapsClientImpl(BingMapsClient client) {
    bingMapsClient = client;
  }
  
  @Override
  public boolean isVerified(String address) {
    return bingMapsClient.getAddress(address).result.isValid;
  }
}