how would you change the test method of the palindrome class so that it considerer all character, not just letters? please identify the statements you would change, and how you would change them: public class Palindrome { public static boolean test(String candidate)   // Returns true if candidate is a palindrome, false otherwise.   {     char ch;                   // current candidate character being processed     int length;                // length of candidate string     char fromStack;            // current character popped from stack     char fromQueue;            // current character dequeued from queue     boolean stillPalindrome;   // true if string might still be a palindrome      StackInterface<Character> stack;   // holds non blank string characters     QueueInterface<Character> queue;   // also holds non blank string characters      // initialize variables and structures     length = candidate.length();     stack = new ArrayBoundedStack<Character>(length);     queue = new ArrayBoundedQueue<Character>(length);      // obtain and handle characters     for (int i = 0; i < length; i++)     {       ch = candidate.charAt(i);       if (Character.isLetter(ch))       {         ch = Character.toLowerCase(ch);         stack.push(ch);         queue.enqueue(ch);       }     }          // determine if palindrome     stillPalindrome = true;     while (stillPalindrome && !stack.isEmpty())     {       fromStack = stack.top();       stack.pop();       fromQueue = queue.dequeue();       if (fromStack != fromQueue)         stillPalindrome = false;     }          // return result     return stillPalindrome;   }}