Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xls/Escher.php
private function readSpContainer()
    {
        $length = Xls::getInt4d($this->data, $this->pos + 4);
        $recordData = substr($this->data, $this->pos + 8, $length);

        // add spContainer to spgrContainer
        $spContainer = new SpContainer();
        $this->object->addChild($spContainer);

        // move stream pointer to next record
        $this->pos += 8 + $length;

        // record is a container, read contents
        $reader = new self($spContainer);
        $escher = $reader->load($recordData);
    }
private function readSpContainer()
    {
        $length = Xls::getInt4d($this->data, $this->pos + 4);
        $recordData = substr($this->data, $this->pos + 8, $length);

        // add spContainer to spgrContainer
        $spContainer = new SpContainer();
        $this->object->addChild($spContainer);

        // move stream pointer to next record
        $this->pos += 8 + $length;

        // record is a container, read contents
        $reader = new self($spContainer);
        $escher = $reader->load($recordData);
    }
Read SpContainer record (Shape Container).