add more tests assert checks and documentation

java_testcode/ThrowNew.java

@@ -0,0 +1,10 @@
+public class ThrowNew extends Throwable {
+
+    public static String message;
+
+    public ThrowNew(String msg) {
+        super(msg);
+        message = msg;
+    }
+
+}

java_testcode/ThrowNewZa.java

@@ -0,0 +1,10 @@
+public class ThrowNewZa extends Throwable {
+
+    public static String message;
+
+    public ThrowNewZa() {
+        super();
+        message = "called";
+    }
+
+}

java_testcode/ThrowNewZa2.java

@@ -0,0 +1,15 @@
+public class ThrowNewZa2 extends Throwable {
+
+    public static String message;
+
+    public ThrowNewZa2() {
+        super();
+        message = "called";
+    }
+
+        public ThrowNewZa2(String arg) {
+            super();
+            message = String.valueOf(arg);
+        }
+
+}

java_testcode/ThrowNewZa3.java

@@ -0,0 +1,10 @@
+public class ThrowNewZa3 extends Throwable {
+
+    public static String message;
+
+    public ThrowNewZa3(Object arg) {
+        super();
+        message = String.valueOf(arg);
+    }
+
+}

java_testcode/ThrowNewZa4.java

@@ -0,0 +1,13 @@
+public abstract class ThrowNewZa4 extends Throwable {
+
+    public static String message;
+
+    public ThrowNewZa4(String arg) {
+        super(arg);
+        message = String.valueOf(arg);
+    }
+
+    public static boolean isAbstractInst(Object obj) {
+        return obj.getClass() == ThrowNewZa4.class;
+    }
+}