Javadoc
Returns a
Set view of the contexts contained in this model. The
set is backed by the model, so changes to the model are reflected in the
set, and vice-versa. If the model is modified while an iteration over the
set is in progress (except through the iterator's own
removeoperation), the results of the iteration are undefined. The set supports
element removal, which removes all statements from the model for which
that element is a context value, via the
Iterator.remove,
Set.remove,
removeAll,
retainAll, and
clear operations. It does not support the
add or
addAll operations if the parameters
subj ,
pred or
obj are null.