public void Test_get_GCD_with_valid_data_returns_expected() { // Arrange. const int expected = 1; const int numInput = 5; var arrayInput = new[] { 2, 3, 4, 5, 6 }; // Act. var result = _greatestCommonDivisor.generalizedGCD(numInput, arrayInput); // Assert. result.Should().Be(expected); }