code: public JsCodeBuilder setOutputVarInited() {
      outputVars.pop();
      outputVars.push(new OutputVar(currOutputVar, /* initialized= */ true));
      currOutputVarIsInited = true;
      return this;
    }
docs: Tells this CodeBuilder that the current output variable has already been initialized. This
  causes {@code initOutputVarIfNecessary} and {@code addToOutputVar} to not add initialization
  code even on the first use of the variable.