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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def clear(self, models=(), commit=True):
 """ Clear all instances of `models` from the database or all models, if not specified. Optional Arguments: `models` -- Models to clear from the database (default = []) If `models` is empty, an empty query is executed which matches all documents in the database. Afterwards, each match is deleted. Otherwise, for each model, a `delete_document` call is issued with the term `XCONTENTTYPE<app_name>.<model_name>`. This will delete all documents with the specified model type. """

        if not models:
            # Because there does not appear to be a "clear all" method,
            # it's much quicker to remove the contents of the `self.path`
            # folder than it is to remove each document one at a time.
            if os.path.exists(self.path):
                shutil.rmtree(self.path)
        else:
            database = self._database(writable=True)
            for model in models:
                database.delete_document(TERM_PREFIXES[DJANGO_CT] + get_model_ct(model))
            database.close()