code: public void encodeBegin(FacesContext facesContext, UIComponent uiComponent) throws IOException
      {
          RendererUtils.checkParamValidity(facesContext, uiComponent, UIData.class);
  
          Map<String, List<ClientBehavior>> behaviors = null;
          if (uiComponent instanceof ClientBehaviorHolder)
          {
              behaviors = ((ClientBehaviorHolder) uiComponent).getClientBehaviors();
              if (!behaviors.isEmpty())
              {
                  ResourceUtils.renderDefaultJsfJsInlineIfNecessary(facesContext, facesContext.getResponseWriter());
              }
          }
          
          beforeTable(facesContext, (UIData) uiComponent);
  
          startTable(facesContext, uiComponent);
      }
docs: Render the necessary bits that come before any actual <i>rows</i> in the table.
  
  @see javax.faces.render.Renderer#encodeBegin(FacesContext, UIComponent)