segmentstore/server/src/main/java/io/pravega/segmentstore/server/tables/SegmentKeyCache.java
/**
     * Same as {@link #evictBefore}, but removes all Cache Entries.
     *
     * @return See {@link #evictBefore}
     */
Same as  #evictBefore, but removes all Cache Entries.
@return See  #evictBefore
Same as #evictBefore but removes all Cache Entries . @return See #evictBefore
synchronized List<CacheEntry> evictAll() {
        val entries = new ArrayList<>(this.cacheEntries.values());
        this.cacheEntries.clear();
        return entries;
    }
synchronized List < CacheEntry > evictAll ( ) { val entries = new ArrayList < > ( this . cacheEntries . values ( ) ) ; this . cacheEntries . clear ( ) ; return entries ; }
Same as {@link #evictBefore}, but removes all Cache Entries.
Same as { @link #evictBefore } but removes all Cache Entries .
// Remove those entries that have a generation below the oldest permissible one.