code: public function translate(string $key, array $arguments = [])
      {
          if (!isset($this->translations[$key])) {
              return null;
          }
  
          if (!$this->hasNamedArguments($arguments)) {
              return $this->translateWithoutNamedArguments($key, $arguments);
          }
  
          return $this->translateWithNamedArguments($key, $arguments);
      }
docs: @param string $key
  @param array  $arguments
  
  @return string|null