ThemeRegistry::get

public ThemeRegistry::get($key)

public function get($key) {
  // If the offset is set but empty, it is a registered theme hook that has
  // not yet been requested. Offsets that do not exist at all were not
  // registered in hook_theme().
  if (isset($this->storage[$key])) {
    return $this->storage[$key];
  }
  elseif (array_key_exists($key, $this->storage)) {
    return $this->resolveCacheMiss($key);
  }
}