code: private PropertyRecord getPropertyRecord(PropertyIdValue property) {
  		if (!this.propertyRecords.containsKey(property)) {
  			PropertyRecord propertyRecord = new PropertyRecord();
  			this.propertyRecords.put(property, propertyRecord);
  			return propertyRecord;
  		} else {
  			return this.propertyRecords.get(property);
  		}
  	}
docs: Returns record where statistics about a property should be stored.
  
  @param property
  the property to initialize
  @return the property record