vds = HifiProduct()         # create a HifiProduct
s1 = Spectrum1d()            # create some Datasets
s2 = Spectrum2d()
s3 = ArrayDataset( )
vds.set( s1 )            # set s1 at number "0001"
vds.set( s2 )            # set s2 at number "0002"
vds.set( s3, 4 )            # set s3 at number "0004"
s4 = vds.get( 1 )            # s4 equals s1
print vds.getCount()        # yields 3 (3 sets in vds)
print vds.getLastIndex()        # yields 4 (last one is at 4)
it = vds.iterator()         # iterator over the datasets.
while it.hasNext(): print it.next().__class__   # print classes
vds.remove( 2 )            # leaves sets at 1 and 4
vds.collapse()            # renumbers sets to 1 and 2
vds.remove()            # removes last one, leaves only nr 1