src/Blocks/BlockContentTemplate.php
public function validateLineType($lineNumber)
    {
        $lineContent = $this->factory
            ->getDataObject()
            ->getLine($lineNumber)
        ;

        return $this->isBlockDelimiterLine($lineContent);
    }
public function validateLineType($lineNumber)
    {
        $lineContent = $this->factory
            ->getDataObject()
            ->getLine($lineNumber)
        ;

        return $this->isBlockDelimiterLine($lineContent);
    }
@param int $lineNumber

@return bool