public FileServiceBuilder maxCacheEntries(int maxCacheEntries) {
        checkState(canSetMaxCacheEntries,
                   "Cannot call maxCacheEntries() if called entryCacheSpec() already.");
        validateNonNegativeParameter(maxCacheEntries, "maxCacheEntries");
        if (maxCacheEntries == 0) {
            entryCacheSpec = null;
        } else {
            entryCacheSpec = String.format("maximumSize=%d", maxCacheEntries);
        }
        canSetEntryCacheSpec = false;
        return this;
    }
Sets the maximum allowed number of cached file entries. If not set, up to {@code 1024} entries
are cached by default.
core/src/main/java/com/linecorp/armeria/server/file/FileServiceBuilder.java