### Question:
PoseWithCovariance extends Message { public static PoseWithCovariance fromJsonString(String jsonString) { return PoseWithCovariance.fromMessage(new Message(jsonString)); } PoseWithCovariance();  PoseWithCovariance(Pose pose);  PoseWithCovariance(Pose pose, double[] covariance); Pose getPose(); double[] getCovariance(); double[][] getCovarianceMatrix(); @Override PoseWithCovariance clone(); static PoseWithCovariance fromJsonString(String jsonString); static PoseWithCovariance fromMessage(Message m); static PoseWithCovariance fromJsonObject(JsonObject jsonObject); static final String FIELD_POSE; static final String FIELD_COVARIANCE; static final String TYPE; static final int COVARIANCE_ROWS; static final int COVARIANCE_COLUMNS; static final int COVARIANCE_SIZE; }### Answer:
@Test public void testFromJsonString() { PoseWithCovariance p = PoseWithCovariance.fromJsonString(p2.toString()); assertEquals(p2.toString(), p.toString()); assertEquals(p2.toJsonObject(), p.toJsonObject()); assertEquals(p2.getMessageType(), p.getMessageType()); assertEquals(p2.getPose(), p.getPose()); assertTrue(Arrays.equals(p2.getCovariance(), p.getCovariance())); assertTrue(Arrays.deepEquals(p2.getCovarianceMatrix(), p.getCovarianceMatrix())); assertNotSame(p2, p); assertNotSame(p2.toString(), p.toString()); assertNotSame(p2.toJsonObject(), p.toJsonObject()); assertNotSame(p2.getPose(), p.getPose()); assertNotSame(p2.getCovariance(), p.getCovariance()); assertNotSame(p2.getCovarianceMatrix(), p.getCovarianceMatrix()); }