public int[] FilterDigitTestOnlyEven(params int[] numbers)
 {
     return(ArrayAlgorithm.FilterDigit(el => el % 2 == 0, numbers));
 }
 public void FilterDigit_ThrowsArgumentException(int digit)
 {
     Assert.Throws <ArgumentException>(
         () => ArrayAlgorithm.FilterDigit(new IsDigitInNumberPredicate(digit), null));
 }
 public int[] FilterDigitTestWithInterface(int digit, params int[] numbers)
 {
     return(ArrayAlgorithm.FilterDigit(new IsDigitInNumberPredicate(digit), numbers));
 }