def init_app(self, app):
    'Initialize a Flask application.'
    if (not hasattr(app, 'extensions')):
        app.extensions = {}
    if ('flask-cli' in app.extensions):
        raise RuntimeError('Flask-CLI application already initialized')
    app.extensions['flask-cli'] = self
    self.setup_pre10(app)
Initialize a Flask application.
def init_app(self, app):
    
    if (not hasattr(app, 'extensions')):
        app.extensions = {}
    if ('flask-cli' in app.extensions):
        raise RuntimeError('Flask-CLI application already initialized')
    app.extensions['flask-cli'] = self
    self.setup_pre10(app)