getMatrix(); $binaryString = ''; for ($rowIndex = 0; $rowIndex < $matrix->getBlockCount(); ++$rowIndex) { for ($columnIndex = 0; $columnIndex < $matrix->getBlockCount(); ++$columnIndex) { $binaryString .= $matrix->getBlockValue($rowIndex, $columnIndex); } $binaryString .= "\n"; } return $binaryString; } public function getMimeType(): string { return 'text/plain'; } }