code: final Status evaluate(final Metric metric) {
  
          if (metric == null || metric.getMetricValue() == null) {
              throw new NullPointerException("Metric value can't be null");
          }
  
          IThreshold thr = thresholdsMap.get(metric.getMetricName());
          if (thr == null) {
              return Status.OK;
          }
  
          return thr.evaluate(metric);
      }
docs: Evaluates the passed in metric against the threshold configured inside
  this evaluator. If the threshold do not refer the passed in metric, then
  it is ignored and the next threshold is checked.
  
  @param metric
  The metric to be checked
  
  @return The status computed according to the rules specified for
  {@link IThreshold#evaluate(Metric)}