question: public void readBytes ( int position , int num , byte [ ] buf ) { if ( Page . pageSize < position + num ) { throw new PageException ( "readBytes is out of bounds" ) ; } if ( buf . length < num ) { throw new PageException ( "num bytes to read is longer than buffer" ) ; } pageData . position ( position ) ; pageData . get ( buf , 0 , num ) ; }
target:  Reads num bytes from offset position into buf.