### Question:
Preconditions { public static void checkGreaterOrEqualToZero(int number, String message) { if (number < 0) { throw new IllegalArgumentException(message); } }  static void checkNotNull(Object object, String message); static void checkNotNullOrEmpty(String string, String message); static void checkGreaterOrEqualToZero(int number, String message); static void checkGreaterThanZero(int number, String message); static boolean isAtLeastAndroidLollipop(); static boolean isAtLeastAndroidMarshmallow();  }### Answer:
@Test(expected = IllegalArgumentException.class) public void shouldThrowAnExceptionWhenValueLowerThanZeroForGreaterOrEqualCheck() { Preconditions.checkGreaterOrEqualToZero(-1, MSG_VALUE_IS_NOT_GREATER_THAN_ZERO); }
@Test public void shouldNotThrowAnythingWhenValueIsGreaterThanZeroForGreaterOrEqualCheck() { Preconditions.checkGreaterOrEqualToZero(1, MSG_VALUE_IS_NOT_GREATER_THAN_ZERO); }
@Test public void shouldNotThrowAnythingWhenValueIsEqualToZero() { Preconditions.checkGreaterOrEqualToZero(0, MSG_VALUE_IS_NOT_GREATER_THAN_ZERO); }