When using JDK 7 (which is the case for the default compiler in Eclipse Helios), org.nuxeo.ecm.core.api.model.impl.ListProperty fails to compile because there is a clash between a method defined in List<Property> and a method defined in AbstractProperty:
Name clash: The method add(E) of type Collection<E> has the same erasure as add(Object) of type Property but does not override it
Name clash: The method add(int, E) of type List<E> has the same erasure as add(int, Object) of type Property but does not override it
Name clash: The method add(Object) of type ListProperty has the same erasure as add(E) of type Collection<E> but does not override it
Name clash: The method set(int, E) of type List<E> has the same erasure as set(int, Object) of type AbstractProperty but does not override it