Returns an immutable set containing only the specified object.
The returned set is serializable.
@param !(T) the class of the objects in the set
@param o the sole object to be stored in the returned set.
@return an immutable set containing only the specified object.
Returns an immutable set containing only the specified object. The returned set is serializable.
@param !(T) the class of the objects in the set @param o the sole object to be stored in the returned set. @return an immutable set containing only the specified object.