public static PlaneIndex of(Model model) {
        return model.getKnowledge(PlaneIndex.class, PlaneIndex::new);
    }
Determines if a service, resource, or operation are considered
part of the data plane or control plane.

<p>The plane is inherited from the top-down and can be overridden
per shape. For example, if a service shape has the
{@code aws.api#controlPlane} shape, then every shape within the closure
of the service inherits this property. If a resource shape defines a
{@code aws.api#controlPlane} or {@code aws.api#dataPlane} trait, then all
shapes within the closure of the resource inherit it. If an operation is
marked with the {@code aws.api#dataPlane} trait, it overrides any plane
traits of the service or resource its bound within.
smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/PlaneIndex.java