code: public function delete($id=false, array $options = array()) {
          if ($this->bulk) {
              return $this->bulk->delete($id, $this->index, $this->type, $options);
          }
          return $this->transport->delete($id, $options);
      }
docs: Flush this index/type combination
  
  @return array
  @param mixed $id If id is supplied, delete that id for this index
  if not wipe the entire index
  @param array $options Parameters to pass to delete action