code: public void addContent(String content) {
          if(_contentBuffer == null) {
              int size = (content != null ? (5 * content.length()) : 1024);
              _contentBuffer = new InternalStringBuilder(size);
          }
  
          _contentBuffer.append(content);
      }
docs: Add content to the content that is being buffered by this tag.  All content
  written by the body of this tag is added to this buffer.  The buffer is rendered
  at the end of the tag's lifecycle if no fatal errors have occurred during this
  tag's lifecycle.
  
  @param content content that this tag should render.