private void comparisons(final CellComparatorImpl c) {
    long now = EnvironmentEdgeManager.currentTime();
    assertTrue(c.compare(
      new KeyValue(Bytes.toBytes(TableName.META_TABLE_NAME.getNameAsString() + ",,1"), now),
      new KeyValue(Bytes.toBytes(TableName.META_TABLE_NAME.getNameAsString() + ",,1"), now)) == 0);
    assertTrue(c.compare(
      new KeyValue(Bytes.toBytes(TableName.META_TABLE_NAME.getNameAsString() + ",,1"), now),
      new KeyValue(Bytes.toBytes(TableName.META_TABLE_NAME.getNameAsString() + ",,2"), now)) < 0);
    assertTrue(c.compare(
      new KeyValue(Bytes.toBytes(TableName.META_TABLE_NAME.getNameAsString() + ",,2"), now),
      new KeyValue(Bytes.toBytes(TableName.META_TABLE_NAME.getNameAsString() + ",,1"), now)) > 0);
  }
Tests cases where rows keys have characters below the ','. See HBASE-832
hbase-common/src/test/java/org/apache/hadoop/hbase/TestKeyValue.java