public AbstractHttpFileBuilder lastModified(boolean lastModifiedEnabled) {
        this.lastModifiedEnabled = lastModifiedEnabled;
        return this;
    }
Sets whether to set the {@code "last-modified"} header automatically. By default,
the {@code "last-modified"} is set automatically.
core/src/main/java/com/linecorp/armeria/server/file/AbstractHttpFileBuilder.java