question: public void mark ( int readlimit ) { stream . mark ( readlimit ) ; if ( markSupported ( ) ) { markpos = framePos ; markPushBackLen = pushBackLen ; if ( markPushBackLen > 0 ) { if ( markPushBackBuffer == null ) { markPushBackBuffer = new byte [ frameSize ] ; } System . arraycopy ( pushBackBuffer , 0 , markPushBackBuffer , 0 , markPushBackLen ) ; } } }
target:  Marks the current position in this audio input stream.