public void CountTest(string str, double expectedResult)
{
var length = new AverageWordsLengthCounter(str);
var result = length.Count();
Assert.That(result, Is.EqualTo(expectedResult));
}
public void CountExceptionTest(string str)
{
var length = new AverageWordsLengthCounter(str);
void Result() => length.Count();
Assert.Throws(Is.TypeOf <ArgumentException>()
.And.Message.EqualTo("Was printed the string without words"),
Result);
}