refactor
refactor
refactor: duplicity removed
refactor: renaming CustomCalendar
refactor: renaming CustomCalendarTest
refactor: renaming CalendarGenerationTest
refactor: renaming CalendarGenerationClient
refactor: extracting year validation tests
red: anEmptyStringIsNotAValidYear
green
refactor
red
green
refactor
refactor
refactor
refactor
refactor
refactor
refactor