code: public function setIndent($pValue)
      {
          if ($pValue > 0) {
              if ($this->getHorizontal() != self::HORIZONTAL_GENERAL &&
                  $this->getHorizontal() != self::HORIZONTAL_LEFT &&
                  $this->getHorizontal() != self::HORIZONTAL_RIGHT) {
                  $pValue = 0; // indent not supported
              }
          }
          if ($this->isSupervisor) {
              $styleArray = $this->getStyleArray(['indent' => $pValue]);
              $this->getActiveSheet()->getStyle($this->getSelectedCells())->applyFromArray($styleArray);
          } else {
              $this->indent = $pValue;
          }
  
          return $this;
      }
docs: Set indent.
  
  @param int $pValue
  
  @return Alignment