[Beta] Delete a model

        See
        https://cloud.google.com/bigquery/docs/reference/rest/v2/models/delete

        Args:
            model (Union[ \
                :class:`~google.cloud.bigquery.model.Model`, \
                :class:`~google.cloud.bigquery.model.ModelReference`, \
                str, \
            ]):
                A reference to the model to delete. If a string is passed in,
                this method attempts to create a model reference from a
                string using
                :func:`google.cloud.bigquery.model.ModelReference.from_string`.
            retry (:class:`google.api_core.retry.Retry`):
                (Optional) How to retry the RPC.
            not_found_ok (bool):
                Defaults to ``False``. If ``True``, ignore "not found" errors
                when deleting the model.

def delete_model(self, model, retry=DEFAULT_RETRY, not_found_ok=False):
        """[Beta] Delete a model

        See
        https://cloud.google.com/bigquery/docs/reference/rest/v2/models/delete

        Args:
            model (Union[ \
                :class:`~google.cloud.bigquery.model.Model`, \
                :class:`~google.cloud.bigquery.model.ModelReference`, \
                str, \
            ]):
                A reference to the model to delete. If a string is passed in,
                this method attempts to create a model reference from a
                string using
                :func:`google.cloud.bigquery.model.ModelReference.from_string`.
            retry (:class:`google.api_core.retry.Retry`):
                (Optional) How to retry the RPC.
            not_found_ok (bool):
                Defaults to ``False``. If ``True``, ignore "not found" errors
                when deleting the model.
        """
        if isinstance(model, str):
            model = ModelReference.from_string(model, default_project=self.project)

        if not isinstance(model, (Model, ModelReference)):
            raise TypeError("model must be a Model or a ModelReference")

        try:
            self._call_api(retry, method="DELETE", path=model.path)
        except google.api_core.exceptions.NotFound:
            if not not_found_ok:
                raise