### Question:
ShellUtils { public static boolean isTarSuccessful (int exitCode) { return exitCode == 0 || exitCode == 1; } private  ShellUtils(); static boolean isTarSuccessful(int exitCode); static boolean isCommentedLine(String s);  }### Answer:
@Test public void isTarSuccessful () { int[] failCodes = { Integer.MIN_VALUE, Integer.MAX_VALUE, 2, -1, 100, -100 }; for (int failCode : failCodes) { assertFalse(ShellUtils.isTarSuccessful(failCode)); } int[] successCodes = { 1, 0 }; for (int successCode : successCodes) { assertTrue(ShellUtils.isTarSuccessful(successCode)); } }