checkNotNull(value);
    Timestamped<V> oldValue = cachingHashMap.put(key, new Timestamped<V>(value, ticker));
    if (oldValue == null) {
      return null;
    }
    alertListenerIfPresent(key, oldValue.getValue(), RemovalCause.REPLACED);
    return oldValue.getValue();
  }

  @CanIgnoreReturnValue
  @Override
  public V remove(Object key) {
    Timestamped<V> stamped = cachingHashMap.remove(key);

        return metadata;
    }

    private static SnapshotVersion addSnapshotVersion(Versioning versioning, Date timestamp, Artifact artifact) {
        int buildNumber = 1;
        // this generates timestamped versions like maven-resolver-provider:
        // https://github.com/apache/maven/blob/03df5f7c639db744a3597c7175c92c8e2a27767b/maven-resolver-provider/src/main/java/org/apache/maven/repository/internal/RemoteSnapshotMetadata.java#L79