public void setEmitAsShape(String emitAsShape) {
        this.emitAsShape = emitAsShape;
    }
This contains a list of shapes for which the additional marshalling
path will not be added. This customization is specifically added for
EC2 where we replace all occurrences of AttributeValue with Value in
the model classes. However the wire representation is not changed.

TODO This customization has been added to preserve backwards
compatiblity of EC2 APIs. This should be removed as part of next major
version bump.
aws-java-sdk-code-generator/src/main/java/com/amazonaws/codegen/model/config/customization/ShapeSubstitution.java