code: func (h *HumanReadablePrinter) TableHandler(columnDefinitions []metav1beta1.TableColumnDefinition, printFunc interface{}) error {
  	printFuncValue := reflect.ValueOf(printFunc)
  	if err := ValidateRowPrintHandlerFunc(printFuncValue); err != nil {
  		utilruntime.HandleError(fmt.Errorf("unable to register print function: %v", err))
  		return err
  	}
  	entry := &handlerEntry{
  		columnDefinitions: columnDefinitions,
  		printFunc:         printFuncValue,
  	}
  
  	objType := printFuncValue.Type().In(0)
  	if _, ok := h.handlerMap[objType]; ok {
  		err := fmt.Errorf("registered duplicate printer for %v", objType)
  		utilruntime.HandleError(err)
  		return err
  	}
  	h.handlerMap[objType] = entry
  	return nil
  }
docs: // TableHandler adds a print handler with a given set of columns to HumanReadablePrinter instance.
  // See ValidateRowPrintHandlerFunc for required method signature.