Context evalContext = context.beginEvalContext(baseNamespaceEnv);
File baseSourceRoot = new File("src/main/R/base");
evalSources(evalContext, baseSourceRoot);
evalContext.evaluate(FunctionCall.newCall(Symbol.get(".onLoad")));
// now serialize them to a lazy-loadable frame
final List<String> omit = Lists.newArrayList(
".Last.value", ".AutoloadEnv", ".BaseNamespaceEnv",