public void BookCalculatesAnAverageGradesFromCLIInput()
{
// arrange
var book = new InMemoryBook("InMemoryBook of Water");
book.AddGrade(60);
book.AddGrade(90);
book.AddGrade(70);
book.AddGrade(60);
book.AddGrade(10);
book.AddGrade(10);
// act
var result = book.GetStatistics();
//assert
Assert.Equal(book.GetMaxGradeCount(), book.GetGrades().Count);
Assert.Equal(280, result.Total);
Assert.Equal(70, result.Average);
Assert.Equal(90, result.High);
Assert.Equal(60, result.Low);
Assert.Equal('C', result.Letter);
}