A component, such as a Component Object Model (COM) object, operates as an
intermediary between an Application Programming Interface (API) extension
or plug-in and a driver. The component allows additional objects to be
aggregated onto the component, and/or sets one or more setting values for
a received request so that an I/O call associated with the request can be
completed in a manner that is compatible with other I/O calls. The
component may also return, in response to a particular request, a stream
index associated with the component.