provider.adjustActionResponseHeaders("text/plain", (k, v) -> headerMap.put(k, v));

        assertEquals(0, headerMap.size());
    }

    @Test
    public void test_write_defaultHeadersOnly() throws Exception {
        final FessConfig fessConfig = createFessConfigWithResponseHeaders("*=X-Def:def\n*=X-Def2:def2");
        FessActionAdjustmentProvider provider = new FessActionAdjustmentProvider(fessConfig);