private String printMultiple(char letter, int count) {
    StringBuilder sb = new StringBuilder(count);
    for (int i = 0; i < count; i++) {
      sb.append(letter);
    }
    return sb.toString();
  }
Note that about half of these tests were relevant for a different implementation approach of
setStartStopRowForPrefixScan. These test cases have been retained to ensure that also the
edge cases found there are still covered.
hbase-server/src/test/java/org/apache/hadoop/hbase/filter/TestScanRowPrefix.java