public static StructurallyExclusive fromNode(Node node) {
            String value = node.expectStringNode()
                    .expectOneOf(
                            StructurallyExclusive.MEMBER.toString(),
                            StructurallyExclusive.TARGET.toString());
            return StructurallyExclusive.valueOf(value.toUpperCase(Locale.ENGLISH));
        }
Only a single structure member can target a shape marked with the trait.
smithy-model/src/main/java/software/amazon/smithy/model/traits/TraitDefinition.java