/**
  * get start row.
  * @return int
  */
 protected function getStartRow()
 {
     $startRow = $this->defaultStartRow;
     if ($this->reader->hasHeader) {
         $startRow++;
     }
     $skip = $this->reader->getSkip();
     if ($skip > 0) {
         $startRow += $skip;
     }
     return $startRow;
 }
 /**
  * Set selected sheets by index.
  * @param array $sheets
  * @return $this
  */
 public function setSelectedSheetsByIndex($sheets = [])
 {
     $sheets = is_array($sheets) ? $sheets : func_get_args();
     $this->reader->setSelectedSheetIndices($sheets);
     return $this;
 }