public DeploymentSpec read(Reader reader) {
        try {
            return read(IOUtils.readAll(reader));
        }
        catch (IOException e) {
            throw new IllegalArgumentException("Could not read deployment spec", e);
        }
    }
Reads a deployment spec from given reader
config-model-api/src/main/java/com/yahoo/config/application/api/xml/DeploymentSpecXmlReader.java