### Question:
TwistWithCovarianceStamped extends Message { public static TwistWithCovarianceStamped fromJsonString(String jsonString) { return TwistWithCovarianceStamped.fromMessage(new Message(jsonString)); } TwistWithCovarianceStamped();  TwistWithCovarianceStamped(Header header, TwistWithCovariance twist); Header getHeader(); TwistWithCovariance getTwist(); @Override TwistWithCovarianceStamped clone(); static TwistWithCovarianceStamped fromJsonString(String jsonString); static TwistWithCovarianceStamped fromMessage(Message m); static TwistWithCovarianceStamped fromJsonObject(
			JsonObject jsonObject); static final String FIELD_HEADER; static final String FIELD_TWIST; static final String TYPE; }### Answer:
@Test public void testFromJsonString() { TwistWithCovarianceStamped p = TwistWithCovarianceStamped .fromJsonString(t1.toString()); assertEquals(t1.toString(), p.toString()); assertEquals(t1.toJsonObject(), p.toJsonObject()); assertEquals(t1.getMessageType(), p.getMessageType()); assertEquals(t1.getHeader(), p.getHeader()); assertEquals(t1.getTwist(), p.getTwist()); assertNotSame(t1, p); assertNotSame(t1.toString(), p.toString()); assertNotSame(t1.toJsonObject(), p.toJsonObject()); }