private static Operator getOperator(String operatorString) {
    for (Operator o : Operator.values()) {
      if (operatorString.equals(o.toString())) {
        return o;
      }
    }
    return null;
  }
Represents a filter that's filtering the metric {@link Record}s.
hbase-hbtop/src/main/java/org/apache/hadoop/hbase/hbtop/RecordFilter.java