protected AbstractCollectionDoubleCollection() 
{

}

 public boolean add(double element) 
{
        return getCollection().add(new Double(element));
}

 public boolean addAll(DoubleCollection c) 
{
        return getCollection().addAll(DoubleCollectionCollection.wrap(c));
}

 public  void clear() 
{
        getCollection().clear();
}

 public boolean contains(double element) 
{
        return getCollection().contains(new Double(element));
}

 public boolean containsAll(DoubleCollection c) 
{
        return getCollection().containsAll(DoubleCollectionCollection.wrap(c));
}

 abstract protected Collection getCollection()

 public boolean isEmpty() 
{
        return getCollection().isEmpty();
}

 public DoubleIterator iterator() 
{
        return IteratorDoubleIterator.wrap(getCollection().iterator());
}

wraps the Iterator returned by my underlying Collection , if any.

 public boolean removeAll(DoubleCollection c) 
{
        return getCollection().removeAll(DoubleCollectionCollection.wrap(c));
}

 public boolean removeElement(double element) 
{
        return getCollection().remove(new Double(element));
}

 public boolean retainAll(DoubleCollection c) 
{
        return getCollection().retainAll(DoubleCollectionCollection.wrap(c));
}

 public int size() 
{
        return getCollection().size();
}

 public double[] toArray() 
{
        Object[] src = getCollection().toArray();
        double[] dest = new double[src.length];
        for(int i=0;i< src.length;i++) {
            dest[i] = ((Number)(src[i])).doubleValue();
        }
        return dest;
}

 public double[] toArray(double[] dest) 
{
        Object[] src = getCollection().toArray();
        if(dest.length <  src.length) {
            dest = new double[src.length];
        }
        for(int i=0;i< src.length;i++) {
            dest[i] = ((Number)(src[i])).doubleValue();
        }
        return dest;
}

 public String toString() 
{
        return getCollection().toString();
}