Render given template file and return the result.

        :param template: Template file path
        :param context: A dict or dict-like object to instantiate given
            template file
        :param opts: Options such as:
            - at_paths: Template search paths
            - at_encoding: Template encoding
            - other keyword options passed to jinja2.Envrionment. Please note
              that 'loader' option is not supported because anytemplate does
              not support to load template except for files

        :return: Rendered string

def render_impl(self, template, context, **opts):
        """
        Render given template file and return the result.

        :param template: Template file path
        :param context: A dict or dict-like object to instantiate given
            template file
        :param opts: Options such as:
            - at_paths: Template search paths
            - at_encoding: Template encoding
            - other keyword options passed to jinja2.Envrionment. Please note
              that 'loader' option is not supported because anytemplate does
              not support to load template except for files

        :return: Rendered string
        """
        return self._render(os.path.basename(template), context, True, **opts)