    def start(self):
        """Start the proxy.

        Will be called during startup if should_start is True.

        **Subclasses must define this method**
        if the proxy is to be started by the Hub
        """
Start the proxy.

Will be called during startup if should_start is True.

**Subclasses must define this method**
if the proxy is to be started by the Hub
jupyterhub/proxy.py