code: protected void __startSection(String name) {
          if (null == name) throw new NullPointerException("section name cannot be null");
          if (null != tmpOut) throw new IllegalStateException("section cannot be nested");
          tmpCaller = __caller;
          __caller = null;
          tmpOut = __buffer;
          __buffer = new StringBuilder();
          section = name;
      }
docs: Start a layout section. Not to be used in user application or template
  
  @param name