/**
  * Dimension of age using the 3 standard age groups
  *
  * @return the dimension
  */
 public CohortDefinitionDimension age() {
   CohortDefinitionDimension dim = new CohortDefinitionDimension();
   dim.setName("Age (<1, <15, 15+)");
   dim.addParameter(new Parameter("onDate", "Date", Date.class));
   dim.addCohortDefinition(
       "<1", map(commonCohortLibrary.agedAtMost(0), "effectiveDate=${onDate}"));
   dim.addCohortDefinition(
       "<15", map(commonCohortLibrary.agedAtMost(14), "effectiveDate=${onDate}"));
   dim.addCohortDefinition(
       "15+", map(commonCohortLibrary.agedAtLeast(15), "effectiveDate=${onDate}"));
   return dim;
 }