@Override
      public boolean advance() {
        boolean hasNext = this.iterator.hasNext();
        this.current = hasNext ? this.iterator.next() : null;
        return hasNext;
      }
Returns CellScanner interface over <code>cellIterable</code> or null if <code>cells</code> is
null
hbase-common/src/main/java/org/apache/hadoop/hbase/CellUtil.java