question: @ Override public String toString ( ) { StringBuilder sb = new StringBuilder ( ) ; sb . append ( '[' ) ; final int end = offset + length ; for ( int i = offset ; i < end ; i ++ ) { if ( i > offset ) { sb . append ( ' ' ) ; } sb . append ( Integer . toHexString ( bytes [ i ] & 0xff ) ) ; } sb . append ( ']' ) ; return sb . toString ( ) ; }
target:  Returns hex encoded bytes, eg [0x6c 0x75 0x63 0x65 0x6e 0x65] 