Trying to import SFZ

[WindowsNT]

This library looks promising. I'm trying to build a SF2 file from a collection of samples. I have a SFz file which I 've parsed it and has, say, 5 sections, each one with a set of samples.

1. For each sample I call sf2.NewSample(...), then I create a SFInstrumentZone from it and push it to a vector.
2. At the end of each section, I create a SFInstrument with that vector of instrument zone. Then I create a SFPresetZone from that instrument, and finally I create a SF2Preset.
3. After all sections are done, I call the Write() method.

What am I doing wrong? The resulting file has only one preset. Is this the right way to import a SFZ?