public boolean isControlPlane(ToShapeId service) {
        return servicePlanes.getOrDefault(service.toShapeId(), null) == Plane.CONTROL;
    }
Checks if the given service shape is part of the control plane.

@param service Service to check.
@return Returns true if the service is part of the control plane.
smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/PlaneIndex.java