public Builder version(String version) {
            switch (version) {
                case "2":
                case "2.0":
                    this.version = "2.0";
                    break;
                case "1":
                case "1.0":
                    this.version = "1.0";
                    break;
                default:
                    throw new IllegalArgumentException("Unsupported Smithy model version: " + version);
            }
            return this;
        }
Sets the IDL version to serialize. Defaults to 2.0.

<p>Version "1.0" serialization cannot be used with {@link #includePrelude}.

@param version IDL version to set. Can be "1", "1.0", "2", or "2.0".
               "1" and "2" are normalized to "1.0" and "2.0".
@return Returns the builder.
smithy-model/src/main/java/software/amazon/smithy/model/shapes/ModelSerializer.java