code: @SuppressWarnings("rawtypes")
      public org.grails.datastore.mapping.query.api.Criteria in(String propertyName, Collection values) {
          if (!validateSimpleExpression()) {
              throwRuntimeException(new IllegalArgumentException("Call to [in] with propertyName [" +
                      propertyName + "] and values [" + values + "] not allowed here."));
          }
  
          propertyName = calculatePropertyName(propertyName);
  
          if(values instanceof List) {
              values = convertArgumentList((List)values);
          }
          addToCriteria(Restrictions.in(propertyName, values == null ? Collections.EMPTY_LIST : values));
          return this;
      }
docs: Applys a "in" contrain on the specified property
  @param propertyName The property name
  @param values A collection of values
  
  @return A Criterion instance