Question $2\mathrm{.}1(25\%)$

From the description of the ISBN validation and formatting rules as well as the method signature above, provide a black$-$box test plan for the tidyISBN$10$or$13$InsertingDashes method using the category partitioning approach. Your test plan should clearly show the parameters, environment conditions, categories, choices and constraints of the problem. Please create a table to report the results with the headers being Parameter$/$Environmental conditions, Categories, Choice, and Constraints. Here is the code for the method:$/**$

$*$ Tidies up an ISBN by first removing stray dashes and

$*$ non$-$numerics. Validates checksum, checks publisher number, and inserts dashes

$*$ where they belong. Discards

$*$ whatever it finds before or after the ISBN.

$*$

$*$ @param rawISBN$10$or$13$ rawISBN text to be tidied, possibly with extra dashes,

$*$ spaces or other junk chars.

$*$

$*$ @return tidied dashed ISBN with lead and trail junk discarded. or an error

$*$ message if the ISBN is invalid.

$*/$

public static String tidyISBN$10$or$13$InsertingDashes$($String rawISBN$10$or$13)\{$

if $($rawISBN$10$or$13==$ null $||$ rawISBN$10$or$13.$length$()==0)\{$

throw new IllegalArgumentException$("$no ISBN"$)$;

$\}$

$//$ strip lead, trail and embedded junk including dashes

final String dashlessISBN $=$ strip$($rawISBN$10$or$13)$;

final int length $=$ dashlessISBN.length$()$;

switch $($length$)\{$

case $10$:

ensureISBN$10$Valid$($dashlessISBN$)$;

return insertDashesInISBN$10$or$13($dashlessISBN$)$;

case $13$:

ensureISBN$13$Valid$($dashlessISBN$)$;

return insertDashesInISBN$10$or$13($dashlessISBN$)$;

default:

throw new IllegalArgumentException$($

"ISBN must be $10$ or $13$ digits long."$)$;

$\}$

$\}$