### Question:
GeocoderNullImpl implements Geocoder { @Override public GeocoderResults geocode(String address, Envelope bbox) { return new GeocoderResults(ERROR_MSG); }  @Override GeocoderResults geocode(String address, Envelope bbox);  }### Answer:
@Test public void testGeocode() { Geocoder nullGeocoder = new GeocoderNullImpl(); GeocoderResults result = nullGeocoder.geocode("121 elm street", null); assertEquals("stub response", GeocoderNullImpl.ERROR_MSG, result.getError()); }