private Model getModel() {
        return Objects.requireNonNull(model.get(), "The dereferenced WeakReference<Model> is null");
    }
Returns true if member is required to have an associated property mapping.

@param memberShape the member shape to check
@return True if input/output member is required to have a property mapping.
smithy-model/src/main/java/software/amazon/smithy/model/knowledge/PropertyBindingIndex.java