question: @ Override public void readFields ( DataInput in ) throws IOException { int length = WritableUtils . readVInt ( in ) ; if ( length > _text . capacity ( ) ) { _text = ByteBuffer . allocate ( length ) ; } in . readFully ( _text . array ( ) , 0 , length ) ; _text . position ( 0 ) ; _text . limit ( length ) ; _map = null ; }
target:  Sets this instance's content from the input.