### Question:
Vector3 extends Message { public static Vector3 fromJsonString(String jsonString) { return Vector3.fromMessage(new Message(jsonString)); } Vector3();  Vector3(double x, double y, double z); double getX(); double getY(); double getZ(); @Override Vector3 clone(); static Vector3 fromJsonString(String jsonString); static Vector3 fromMessage(Message m); static Vector3 fromJsonObject(JsonObject jsonObject); static final String FIELD_X; static final String FIELD_Y; static final String FIELD_Z; static final String TYPE; }### Answer:
@Test public void testFromJsonString() { Vector3 p = Vector3.fromJsonString(v1.toString()); assertEquals(v1.toString(), p.toString()); assertEquals(v1.toJsonObject(), p.toJsonObject()); assertEquals(v1.getMessageType(), p.getMessageType()); assertEquals(v1.getX(), p.getX(), 0); assertEquals(v1.getY(), p.getY(), 0); assertEquals(v1.getZ(), p.getZ(), 0); assertNotSame(v1, p); assertNotSame(v1.toString(), p.toString()); assertNotSame(v1.toJsonObject(), p.toJsonObject()); }