73     public function addSearch(BaseSearch $search, ?string $key = null): self  argument
76             $this->_searches[$key] = $search;
78             $this->_searches[] = $search;
91         foreach ($searches as $key => $search) {
92             $this->addSearch($search, $key);
129     public function search(): ResultSet  function in Elastica\\Multi\\Search
147         foreach ($this->getSearches() as $search) {
148             $data .= $this->_getSearchData($search);
154     protected function _getSearchData(BaseSearch $search): string  argument
156         $header = $this->_getSearchDataHeader($search);
159         $query = $search->getQuery();
162         $queryOptions = \array_diff_key($search->getOptions(), \array_flip(self::$HEADER_OPTIONS));
170     protected function _getSearchDataHeader(BaseSearch $search): array  argument
172         $header = $search->getOptions();
174         if ($search->hasIndices()) {
175             $header['index'] = $search->getIndices();