def drop_if_exists(self):
        return self._add_command('drop_if_exists')
Given list of ``Tag`` instances, creates a string representation of
dataset/ETHPy150Open sdispater/orator/orator/schema/blueprint.py/Blueprint.drop_if_exists--crossover with--dataset/ETHPy150Open alex/django-taggit/taggit/utils.py/_edit_string_for_tags