src/Element/AbstractElement.php
public function getBracketBeforeChildren(int $indentation = null): string
    {
        $line = $this->getIndentedString(self::OPEN_BRACKET, $indentation);
        $this->setIndentation(($indentation === null ? $this->getIndentation() : $indentation) + 1);
        return $line;
    }
public function getBracketBeforeChildren(int $indentation = null): string
    {
        $line = $this->getIndentedString(self::OPEN_BRACKET, $indentation);
        $this->setIndentation(($indentation === null ? $this->getIndentation() : $indentation) + 1);
        return $line;
    }
Allows to generate content before children content is generated
@param int $indentation
@return string