public B dismiss404() {
    this.dismiss404 = true;
    return thisB;
  }
This flag indicates that the {@link #decoder(Decoder) decoder} should process responses with
404 status, specifically returning null or empty instead of throwing {@link FeignException}.

<p>All first-party (ex gson) decoders return well-known empty values defined by {@link
Util#emptyValueOf}. To customize further, wrap an existing {@link #decoder(Decoder) decoder} or
make your own.

<p>This flag only works with 404, as opposed to all or arbitrary status codes. This was an
explicit decision: 404 -> empty is safe, common and doesn't complicate redirection, retry or
fallback policy. If your server returns a different status for not-found, correct via a custom
{@link #client(Client) client}.

@since 11.9
core/src/main/java/feign/BaseBuilder.java