code: protected void __endSection(boolean def) {
          if (null == tmpOut && null == tmpCaller) throw new IllegalStateException("section has not been started");
          __addLayoutSection(section, __buffer.toString(), def);
          __buffer = tmpOut;
          __caller = tmpCaller;
          tmpOut = null;
          tmpCaller = null;
      }
docs: End a layout section with a boolean flag mark if it is a default content or not.
  Not to be used in user application or template
  
  @param def