code: public static <T extends Number & Comparable<T>> Aggregation<T> sum(Property<?, T> property) {
  		return new Sum<T>(property);
  	}
docs: Get the sum aggregation implementation for the specified property.
  
  @param <T> The property value type that this sum aggregation aggregates.
  @param property The metamodel property that this sum aggregation
  aggregates.
  @return Sum aggregation implementation for the specified property.