Grid/Export/Export.php
public function setTemplate($template)
    {
        if (is_string($template)) {
            if (substr($template, 0, 8) === '__SELF__') {
                $this->templates = $this->getTemplatesFromString(substr($template, 8));
                $this->templates[] = $this->twig->loadTemplate(static::DEFAULT_TEMPLATE);
            } else {
                $this->templates = $this->getTemplatesFromString($template);
            }
        } elseif ($this->templates === null) {
            $this->templates[] = $this->twig->loadTemplate(static::DEFAULT_TEMPLATE);
        } else {
            throw new \Exception('Unable to load template');
        }

        return $this;
    }
public function setTemplate($template)
    {
        if (is_string($template)) {
            if (substr($template, 0, 8) === '__SELF__') {
                $this->templates = $this->getTemplatesFromString(substr($template, 8));
                $this->templates[] = $this->twig->loadTemplate(static::DEFAULT_TEMPLATE);
            } else {
                $this->templates = $this->getTemplatesFromString($template);
            }
        } elseif ($this->templates === null) {
            $this->templates[] = $this->twig->loadTemplate(static::DEFAULT_TEMPLATE);
        } else {
            throw new \Exception('Unable to load template');
        }

        return $this;
    }
set template.

@param \Twig_TemplateInterface|string $template

@throws \Exception

@return \APY\DataGridBundle\Grid\Export\Export