nsIMultiplexInputStream Interface

 Appends a stream to the end of the streams. The cursor of the stream
 should be located at the beginning of the stream if the implementation
 of this nsIMultiplexInputStream also is used as an nsISeekableStream.
 @param stream  stream to append

void appendStream(in nsIInputStream stream)

 Get stream at specified index.
 @param index   return stream at this index, must be < count
 @return        stream at specified index

nsIInputStream getStream(in unsigned long index)

 Insert a stream at specified index.  If the cursor of this stream is at
 the beginning of the stream at index, the cursor will be placed at the
 beginning of the inserted stream instead.
 The cursor of the new stream should be located at the beginning of the
 stream if the implementation of this nsIMultiplexInputStream also is
 used as an nsISeekableStream.
 @param stream  stream to insert
 @param index   index to insert stream at, must be <= count

void insertStream(in nsIInputStream stream, in unsigned long index)

 Remove stream at specified index. If this stream is the one currently
 being read the readcursor is moved to the beginning of the next
 stream
 @param index   remove stream at this index, must be < count

void removeStream(in unsigned long index)