boolean isDeletedAt(MockId id, long referenceTimeMs) {
    IndexValue value = getExpectedValue(id, false);
    Offset deleteIndexSegmentStartOffset = value.isDelete() ? referenceIndex.floorKey(value.getOffset()) : null;
    return deleteIndexSegmentStartOffset != null
        && lastModifiedTimesInSecs.get(deleteIndexSegmentStartOffset) * Time.MsPerSec < referenceTimeMs;
  }
Returns {@code true} if the {@code id} is considered deleted at {@code referenceTimeMs}.
@param id the {@link MockId} to check.
@param referenceTimeMs the reference time in ms at which the check needs to be performed.
@return {@code true} if the {@code id} is considered deleted at {@code referenceTimeMs}. {@code false} otherwise.
ambry-store/src/test/java/com/github/ambry/store/CuratedLogIndexState.java