Describe the issue

For importing a pre-existing Application Listener using the "from_application_listener_attributes" static method, the docs lists the "security_group" parameter as "Optional". When attempting to import an existing Application listener without specifying a security group parameter you are met with the following error during "cdk synth":

Error: Either securityGroup or securityGroupId must be specified to import an application listener.

Adding the security group allows for successful "cdk synth" and "cdk deploy" commands. The above error message makes it so that the security_group parameter is not optional as listed in the docs.

Links

from_application_listener_attributes:
https://docs.aws.amazon.com/cdk/api/v2/python/aws_cdk.aws_elasticloadbalancingv2/ApplicationListener.html#aws_cdk.aws_elasticloadbalancingv2.ApplicationListener.from_application_listener_attributes