private static boolean isContentAlwaysEmpty(HttpMethod method) {
        switch (method) {
            case CONNECT:
            case GET:
            case HEAD:
            case OPTIONS:
            case TRACE:
                return true;
            default:
                return false;
        }
    }
Removes HTTP/1 specified headers from a mutable headers map.
Functionally this method is expected to behave the same as
{@link #toArmeria(io.netty.handler.codec.http.HttpHeaders, HttpHeadersBuilder)}.
This method should be preferred going forward as we continue implementing zero-copy
for HTTP1 en/decoders.
core/src/main/java/com/linecorp/armeria/internal/common/ArmeriaHttpUtil.java