* @param toIndex          the destination index name
     * @param waitForCompletion whether to wait for the operation to complete
     * @return true if the copy operation was successful, false otherwise
     */
    public boolean copyDocIndex(final String fromIndex, final String toIndex, final boolean waitForCompletion) {
        final FessConfig fessConfig = ComponentUtil.getFessConfig();

        }

        @Override
        public void start() {
            // Mock implementation
        }

        // Custom join method to avoid overriding final Thread.join()
        public void waitForCompletion(long millis) {
            // Mock implementation
        }

        @Override
        public String getOutput() {
            return output;
        }
    }