def apply_pool_defaults(self, app, options):
        """
        Set default engine options. We enable `pool_pre_ping` to be the default value.
        """
        options = super().apply_pool_defaults(app, options)
        options["pool_pre_ping"] = True
        return options

        Set default engine options. We enable `pool_pre_ping` to be the default value.
        
lemur/extensions.py