### Question:
Preconditions { public static void checkArgument(final boolean expression, @NonNull final String errorMessage) { if (!expression) { throw new IllegalArgumentException(errorMessage); } } private  Preconditions(); static void checkState(final boolean expression, @NonNull final String errorMessage); static void checkArgument(final boolean expression, @NonNull final String errorMessage); @SuppressWarnings("ConstantConditions") @NonNull static T checkNotNull(@NonNull final T object);  }### Answer:
@Test public void shouldNotThrowExceptionForCheckArgumentWithTrueExpression() { checkArgument(true, ""); }
@Test(expected = IllegalArgumentException.class) public void shouldThrowIllegalArgumentExceptionForCheckArgumentWithFalseExpression() { checkArgument(false, ""); }