public Optional<Path> createPathToInputMember(ToShapeId operationId, String memberName) {
        return createPathTo(operationId, memberName, RelationshipType.INPUT);
    }
Creates a {@code Path} to an operation input member if it exists.

@param operationId Operation to start from.
@param memberName Input member name to find in the operation input.
@return Returns the optionally found {@code Path} to the member.
smithy-model/src/main/java/software/amazon/smithy/model/selector/PathFinder.java