'Collects any information that\'s necessary to execute this
transformer\'s transform method.'

@classmethod
def collect(cls, block_structure):

    block_structure.request_xblock_fields('days_early_for_beta')
    collect_merged_date_field(block_structure, transformer=cls, xblock_field_name='start', merged_field_name=cls.MERGED_START_DATE, default_date=DEFAULT_START_DATE, func_merge_parents=min, func_merge_ancestors=max)
