irectly with these interfaces.
Instead, it deals with classes that <em>implement</em> these
interfaces.  
The application gets these classes either as part of a
repertoire of extended operations standardized through the IETF, or
from directory vendors for vendor-specific extended operations.
The request classes should have constructors that accept
arguments in a type-safe and user-friendly manner, while the
response classes should have access methods for getting the data
of the response in a type-safe and u