@Override
    default ResponseHeaders withMutations(Consumer<HttpHeadersBuilder> mutator) {
        return (ResponseHeaders) HttpHeaders.super.withMutations(mutator);
    }
Returns a new {@link ResponseHeaders} copied from the specified {@link HttpHeaders}.

@throws IllegalArgumentException if the specified {@link HttpHeaders} does not have
                                 {@code ":status"} header.
core/src/main/java/com/linecorp/armeria/common/ResponseHeaders.java