### Question:
RValueExpression extends JsonObject { @Override public JsonNode toJson() { switch (type) { case _value: return value.toJson(); case _dereference: ObjectNode node = getFactory().objectNode(); node.put("$valueof", path.toString()); return node; default: return getFactory().nullNode(); } } RValueExpression(Value value);  RValueExpression(Path p); private  RValueExpression(Value value, Path path, RValueType type); static RValueExpression nullRValue(); Value getValue(); Path getPath(); RValueType getType(); @Override JsonNode toJson(); static RValueExpression fromJson(JsonNode node); @Override int hashCode(); @Override boolean equals(Object obj); static final RValueExpression NULL; }### Answer:
@Test public void testToJson() throws IOException { RValueExpression instance = new RValueExpression(new Value("test")); JsonNode expResult = JsonUtils.json("\"test\""); JsonNode result = instance.toJson(); assertEquals(expResult, result); }