code: public function addTheme($name, $styles, bool $override = false): void
      {
          if (\array_key_exists($name, $this->themes) && false === $override) {
              throw new \RuntimeException('Theme [' . $name . '] is already set.');
          }
          
          $styles = $this->refineStyles($styles);
  
          foreach ($styles as $style) {
              if (!$this->isValid($style)) {
                  throw new InvalidStyleException($style);
              }
          }
          $this->themes[$name] = $styles;
      }
docs: {@inheritdoc}