### Question:
TwistWithCovarianceStamped extends Message { @Override public TwistWithCovarianceStamped clone() { return new TwistWithCovarianceStamped(this.header, this.twist); } 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 testClone() { TwistWithCovarianceStamped clone = t1.clone(); assertEquals(t1.toString(), clone.toString()); assertEquals(t1.toJsonObject(), clone.toJsonObject()); assertEquals(t1.getMessageType(), clone.getMessageType()); assertEquals(t1.getHeader(), clone.getHeader()); assertEquals(t1.getTwist(), clone.getTwist()); assertNotSame(t1, clone); assertNotSame(t1.toString(), clone.toString()); assertNotSame(t1.toJsonObject(), clone.toJsonObject()); }