[wsif] zip2geo sample questions

In the WSDL for the Zip2Geo sample, the Message "GetLatLongSoapIn" contains
a single part of "parameters" which references the element "GetLatLong"
The sample code that invokes an operation using this message, the schema is
unwrapped and two input parts are being set vs. the single part that is
specified in the WSDL document.  Also, this appears to be the case only
when style="document" and use="literal".  Does anyone know the reasoning
behind this, i.e., the unwrapping of the element reference?  Also, what
happens is the element references a sufficiently complexType whereby the
complexType is several layers deep and primitive types exist at each level?
Is a input part then required for each of those primitives?

Thanks much.

Rhett DeWall
Sybase Inc.
3665 Discovery Drive
Boulder, CO  80303
303/413-4163