def init_cli(self, app):
        """
        Initialize the Flask CLI support in case it was enabled for the
        app.

        Works with both Flask>=1.0's CLI support as well as the backport
        in the Flask-CLI package for Flask<1.0.
        """
        # in case click isn't installed after all
        if click is None:
            raise RuntimeError('Cannot import click. Is it installed?')
        # only add commands if we have a click context available
        from .cli import add_commands
        add_commands(app.cli, self)
Initialize the Flask CLI support in case it was enabled for the
        app.

        Works with both Flask>=1.0's CLI support as well as the backport
        in the Flask-CLI package for Flask<1.0.