    deferred class
    	IO_MEDIUM

    Ancestors
    	DISPOSABLE*
    	STRING_HANDLER

    Descendants
    	FILE*
    	SOCKET
    	STREAM

    Clients
    	IO_MEDIUM*
    	KL_INPUT_STREAM_ROUTINES
    	KL_OUTPUT_STREAM_ROUTINES
    	MEDIUM_POLLER
    	POLL_COMMAND*
    	POLL_MASK
    	SED_MEDIUM_READER_WRITER
    	SED_MEDIUM_READER_WRITER_1
    	STORABLE
    	WEL_DIB

    Suppliers
    	BOOLEAN
    	INTEGER_32
    	IO_MEDIUM*
    	MANAGED_POINTER