### Question:
TwistWithCovariance extends Message { public static TwistWithCovariance fromMessage(Message m) { return TwistWithCovariance.fromJsonObject(m.toJsonObject()); } TwistWithCovariance();  TwistWithCovariance(Twist twist);  TwistWithCovariance(Twist twist, double[] covariance); Twist getTwist(); double[] getCovariance(); double[][] getCovarianceMatrix(); @Override TwistWithCovariance clone(); static TwistWithCovariance fromJsonString(String jsonString); static TwistWithCovariance fromMessage(Message m); static TwistWithCovariance fromJsonObject(JsonObject jsonObject); static final String FIELD_TWIST; 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 testFromMessage() { Message m = new Message(p2.toString()); TwistWithCovariance p = TwistWithCovariance.fromMessage(m); assertEquals(p2.toString(), p.toString()); assertEquals(p2.toJsonObject(), p.toJsonObject()); assertEquals(p2.getMessageType(), p.getMessageType()); assertEquals(p2.getTwist(), p.getTwist()); 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.getTwist(), p.getTwist()); assertNotSame(p2.getCovariance(), p.getCovariance()); assertNotSame(p2.getCovarianceMatrix(), p.getCovarianceMatrix()); }