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

*** 303,308 ****
--- 303,314 ----
       * @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);
  }