This class is an extension of NamingManager. It contains methods
for use by service providers for accessing object factories and
state factories, and for getting continuation contexts for
DirectoryManager is safe for concurrent access by multiple threads.
Except as otherwise noted,
a Name, Attributes, or environment parameter
passed to any method is owned by the caller.
The implementation will not modify the object or keep a reference
to it, although it may keep a reference to a clone or copy.