'Sets the release dates of the chapter, sequential, and vertical'

def _update_release_dates(self, chapter_start, sequential_start, vertical_start):

    self.chapter.start = chapter_start
    self.chapter = self.store.update_item(self.chapter, ModuleStoreEnum.UserID.test)
    self.sequential.start = sequential_start
    self.sequential = self.store.update_item(self.sequential, ModuleStoreEnum.UserID.test)
    self.vertical.start = vertical_start
    self.vertical = self.store.update_item(self.vertical, ModuleStoreEnum.UserID.test)
