### Question:
JsonUtils { public static JsonNode json(String s) throws IOException { return json(s, false); } private  JsonUtils(); static ObjectMapper getObjectMapper(); static JsonNode json(String s); static JsonNode json(String s, boolean systemPropertySubstitution); static JsonNode json(InputStream stream, boolean systemPropertySubstitution); static JsonNode json(InputStream stream); static JsonNode json(Reader reader); static JsonNode json(Reader reader, boolean systemPropertySubstitution); static Object valueFromJson(ValueNode node); static ValueNode valueToJson(Object value); static Object fromJson(JsonNode json); static JsonNode toJson(Object obj); static String prettyPrint(JsonNode node); static void prettyPrint(StringBuilder bld, JsonNode node); static String toJson(String[] strings); static JsonSchema loadSchema(String resourceName); static String jsonSchemaValidation(JsonSchema schema, JsonNode node); static int size(JsonNode node);  }### Answer:
@Test @Ignore public void testJson() throws Exception { String s = ""; JsonNode expResult = null; JsonNode result = JsonUtils.json(s); assertEquals(expResult, result); fail("The test case is a prototype."); }
@Test public void testJson_system_properties() throws Exception { String jvmVersion = System.getProperty("java.vm.version"); String s = "{\"test\":\"${java.vm.version}\"}"; JsonNode result = JsonUtils.json(s, true); Assert.assertNotNull(result); Assert.assertEquals(jvmVersion, result.get("test").asText()); }
@Test public void testJson_system_properties_no_match() throws Exception { String s = "{\"test\":\"${something.that.does.not.exist}\"}"; JsonNode result = JsonUtils.json(s, true); Assert.assertNotNull(result); Assert.assertEquals("${something.that.does.not.exist}", result.get("test").asText()); }
@Test @Ignore public void testJsonWithNoInput() throws Exception { JsonUtils.json((String) null); fail("The test case is a prototype."); }
@Test @Ignore public void testJsonWithInvalidJSONInput() throws Exception { JsonUtils.json("a"); fail("The test case is a prototype."); }