public RouteBuilder consumes(Iterable<MediaType> consumeTypes) {
        ensureUniqueMediaTypes(consumeTypes, "consumeTypes");
        consumes = ImmutableSet.copyOf(consumeTypes);
        return this;
    }
Sets the {@link Route} to consume the specified {@link MediaType}s. If not set,
the mapped {@link HttpService} accepts {@link HttpRequest}s that have any
{@link HttpHeaderNames#CONTENT_TYPE}. In order to get this work, {@link #methods(Iterable)} must be set.
core/src/main/java/com/linecorp/armeria/server/RouteBuilder.java