public AggregatedHttpFile build() {
        return new HttpDataFile(content, clock(), lastModifiedMillis,
                                isDateEnabled(), isLastModifiedEnabled(),
                                entityTagFunction(), buildHeaders());
    }
Returns a newly created {@link AggregatedHttpFile} with the properties configured so far.
core/src/main/java/com/linecorp/armeria/server/file/AggregatedHttpFileBuilder.java