this is my coding that I try to do I don't know something is missing if it possible look at it fix the code

language: Java software Engineer class

ipse workspace - Assignment3/src/edu/qc/seclass/MyCustomString.java - Eclipse IDE Edit Source Refactor Navigate Search Project Run Window Help MyCustomString Test.java MyCustomString.java MyCustomString interface.java 28 30 31 return count; 32 33 34 @Override public String getEverythCharacterFromBeginningOrend(int n, boolean start FromEnd) throws NullPointerException, IllegalArgumentExcept int i =1; int index = i*n - 1; String input = this.my InputString; String result = ""; char letter= 'o'; 39 if (n > input. length() { throw new IllegalArgumentException(); while (index input.length() { throw new IllegalArgumentException(); while (index/src/edu/qc/seclass. 6. Your second task is to develop a set of JUnit 4.0 test cases for class MyCustomString. 0 You should create several test cases for each method that implements a method in the interface, except for getters and setters (i.e., the first two methods). Make sure that every test method has a suitable oracle (i.e., either an assertion or an expected exception), that the tests are not trivial (i.e., have a specific purpose). In other words, each test should (1) test a specific piece of functionality and (2) check that such piece of functionality behaves as expected. In addition, for each exception that can be thrown by a method Mand is explicitly mentioned in M's documentation, there should be at least one test for M that results in that expected exception. For example, at least three of the tests for method convert DigitsToNamesInSubstring should result in expected exceptions: One for IllegalArgumentException . One for MyIndexOutOfBounds Exception One for NullPointerException When testing for an expected exception, make sure to use the @Test(expected ) notation. For example: @Test (expected = MyIndexOutOfBounds Exception.class) public void testConvertDigitsToNamesInSubstring(1) o To make your job a little easier, the archive also contains, in directory

/test, a test class edu.qc.seclass.MyCustomStringTest, which provides a skeleton for the