@Override
  public BigDecimal increment(BigDecimal bd) {
    return bd == null ? null : bd.add(BigDecimal.ONE);
  }
ColumnInterpreter for doing Aggregation's with BigDecimal columns. This class is required at the
RegionServer also.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/coprocessor/BigDecimalColumnInterpreter.java