public void process(Block block)
{
checkNotNull(block, "block is null");
if (dictionaryBuilder == null) {
dictionaryBuilder = new ChannelSetBuilder(block.getType(), MAX_UNIQUE_COUNT, null);
}
for (int position = 0; position < block.getPositionCount(); position++) {
// update run length stats
Block value = block.getSingleValueBlock(position);