code: public function resolve($templatePath)
      {
          $templatePathReal = realpath($templatePath);
  
          if ($templatePathReal === false) {
              throw new \Exception(
                  'Template file does not exist: ' . $templatePath
              );
          }
  
          if ($this->hasCache($templatePathReal)) {
              return $this->getCache($templatePathReal);
          }
  
          $template = file_get_contents(
              $templatePathReal
          );
  
          $this->setCache($templatePathReal, $template);
  
          return $template;
      }
docs: Resolve a template name to mustache content or a set of tokens.
  
  @param string $templatePath
  
  @return array|bool|null|string
  @throws \Exception
  @throws \Psr\SimpleCache\InvalidArgumentException