public Shape expectShape(ShapeId id) {
        return getShape(id).orElseThrow(() -> new ExpectationNotMetException(
                "Shape not found in model: " + id,
                SourceLocation.NONE));
    }
Attempts to retrieve a {@link Shape} by {@link ShapeId} and
throws if not found.

@param id Shape to retrieve by ID.
@return Returns the shape.
@throws ExpectationNotMetException if the shape is not found.
smithy-model/src/main/java/software/amazon/smithy/model/Model.java