public List<Pair<ByteBuffer, IColumn>> getPrefetchedList(ByteBuffer rowKey, ByteBuffer cql3ColumnName)
{
if (prefetchedLists == null)
return Collections.emptyList();
ColumnGroupMap m = prefetchedLists.get(rowKey);
return m == null ? Collections.<Pair<ByteBuffer, IColumn>>emptyList() : m.getCollection(cql3ColumnName);
}