update readme

Author: stevehu

README.md

@@ -143,8 +143,8 @@ and JsonNode from String.
 ## Known issues
 
 I have just updated the test suites from the [official website](https://github.com/json-schema-org/JSON-Schema-Test-Suite) as the old ones were copied from another
-Java validator. Now there are several issues that need to be addressed. All of them are edge cases
-in my opinion but need to be investigated.
+Java validator. Now there are several issues that need to be addressed. All of them are edge cases in my opinion but need to be investigated. As my old test suites
+were inherited from another Java JSON Schema Validator, I guess other Java Validator would have the same issue as these issues are in the Java Language itself.
 
 [#7](https://github.com/networknt/json-schema-validator/issues/7)