public void GetPriceOfTheConnection_ValidPhoneAndTimeOfConnection_CorrectValue()
{
//Arrange
const int TIME_OF_CONNECTION = 50;
const decimal TOTAL_COST = 50 * 0.60M / 60;
var dataObjectMapperMock = new Mock <IDataObjectMapper>();
var subscribersSystemDbContextMock = new Mock <ISubscribersSystemDbContext>();
var phoneService = new PhoneService(() => subscribersSystemDbContextMock.Object, dataObjectMapperMock.Object);
//Act
var result = phoneService.GetPriceOfTheConnection(validPhone, TIME_OF_CONNECTION);
//Assert
Assert.AreEqual(TOTAL_COST, result);
}