code: public static void setDebugFlags(JShell state, int flags) {
          if (debugMap == null) {
              debugMap = new HashMap<>();
          }
          debugMap.put(state, flags);
      }
docs: Sets which debug flags are enabled for a given JShell instance. The flags
  are or'ed bits as defined in {@code DBG_*}.
  
  @param state the JShell instance
  @param flags the or'ed debug bits