src/java.base/share/classes/jdk/internal/misc/JavaLangAccess.java

@@ -303,6 +303,12 @@
      * @param s the string to encode
      * @return the encoded bytes in utf8
      * @throws IllegalArgumentException for malformed surrogates
      */
     byte[] getBytesUTF8NoRepl(String s);
+
+    /**
+     * Set the cause of Throwable
+     * @param cause set t's cause to new value
+     */
+    void setCause(Throwable t, Throwable cause);
 }