/**
  * load all tiles
  *
  * @param array $leftUpCorner
  * @param array $rightDownCorner
  * @return array
  */
 protected function _getTiles($leftUpCorner, $rightDownCorner)
 {
     $tiles = array();
     $leftUpTilesNumber = $this->_tileSource->getTileNumbersFromCoordinates($leftUpCorner['lon'], $leftUpCorner['lat'], $this->_worldMap->getZoom());
     $rightDownTilesNumber = $this->_tileSource->getTileNumbersFromCoordinates($rightDownCorner['lon'], $rightDownCorner['lat'], $this->_worldMap->getZoom());
     $tilesGetter = new TilesGetter($leftUpTilesNumber, $rightDownTilesNumber, $this->_tileSource, $this->_worldMap);
     $tilesGetter->startLoading();
     while (!$tilesGetter->isLoaded()) {
         //wating for finishing loading
     }
     return $tilesGetter->getTiles();
 }