@Override
    public boolean matches(T argument) {
      if (!expected.getClass().isAssignableFrom(argument.getClass())) {
        return false;
      }
      Mutation actual = (Mutation) argument;
      if (!Arrays.equals(expected.getRow(), actual.getRow())) {
        return false;
      }
      if (expected.size() != actual.size()) {
        return false;
      }
      NavigableMap<byte[], List<Cell>> expectedCells = expected.getFamilyCellMap();
      NavigableMap<byte[], List<Cell>> actualCells = actual.getFamilyCellMap();
      Entry<byte[], List<Cell>> expectedEntry = expectedCells.entrySet().iterator().next();
      Entry<byte[], List<Cell>> actualEntry = actualCells.entrySet().iterator().next();
      if (!Arrays.equals(expectedEntry.getKey(), actualEntry.getKey())) {
        return false;
      }
      return Objects.equals(expectedEntry.getValue(), actualEntry.getValue());
    }
Quick hack to verify a Mutation with one column.
hbase-server/src/test/java/org/apache/hadoop/hbase/quotas/TestTableSpaceQuotaViolationNotifier.java