public static String stripMaliciousHeaderChars(@Nullable String input) {
        if (input == null) {
            return null;
        }
        // TODO(carl-mastrangelo): implement this more efficiently.
        for (char c : MALICIOUS_HEADER_CHARS) {
            if (input.indexOf(c) != -1) {
                input = input.replace(Character.toString(c), "");
            }
        }
        return input;
    }
@Test
    void stripMaliciousHeaderChars() {
        assertEquals("something", HttpUtils.stripMaliciousHeaderChars("some\r\nthing"));
        assertEquals("some thing", HttpUtils.stripMaliciousHeaderChars("some thing"));
        assertEquals("something", HttpUtils.stripMaliciousHeaderChars("\nsome\r\nthing\r"));
        assertEquals("", HttpUtils.stripMaliciousHeaderChars("\r"));
        assertEquals("", HttpUtils.stripMaliciousHeaderChars(""));
        assertNull(HttpUtils.stripMaliciousHeaderChars(null));
    }