anchor.diff:  // adds value 992 to simple.histogram
   from("direct:in")
       .setHeader(MetricsConstants.HEADER_HISTOGRAM_VALUE, constant(992L))
  -    .to("metric:histogram:simple.histogram?value=700")
  +    .to("metrics:histogram:simple.histogram?value=700")
       .to("direct:out")
   
   ----
  
positive.code: 
   
  
  From Java code tou can get hold of
  the `com.codahale.metrics.MetricRegistry` from the
  `org.apache.camel.component.metrics.routepolicy.MetricsRegistryService`
  as shown below:
  
negative.code: // update gauge simple.gauge by a String literal "myUpdatedSubject"
  from("direct:in")
      .setHeader(MetricsConstants.HEADER_GAUGE_SUBJECT, constant("myUpdatedSubject"))
      .to("metrics:counter:simple.gauge?subject=#mySubjectBean")
      .to("direct:out");
  ----
  
  