This is project is part of the C# language training plan. Please read the following guidelines before start.

The basic part contains test with the following form

[Fact]
public void should_take_first_n_elements_using_take()
{
    var sequence = new[] {1, 2, 3, 4, 5};

    IEnumerable<int> filteredElements = sequence.Take(3);

    // please update variable value to fix the test.
    IEnumerable<int> expectedResult = new[] {1, 2, 3, 4, 5};

    Assert.Equal(expectedResult, filteredElements);
}

Each test containing in this project will fail by default. DO NOT run the test first! Please read the test to get a basic idea, then try to correct the test following the hint comment.

For example. In the test above, you can only modify the line after the comment

// please update variable value to fix the test.
IEnumerable<int> expectedResult = new[] {1, 2, 3, 4, 5};

Please run the test again after modification to see if the test is corrected. If it is succeeded, please check all the codes related to this test (including the dependency demo class) and make sure you have fully understood them; while, if it fails again, please check the reason and try to correct it again.

Please correct all the test FOLLOWING THE SEQUENCE NUMBER to make your life easy.