Filesystem/CsvResource.php
public function writeRaw(array $fields): int
    {
        $this->assertOpened();
        ++$this->currentLine;

        return fputcsv($this->handler, $fields, $this->delimiter, $this->enclosure, $this->escape);
    }
public function writeRaw(array $fields): int
    {
        $this->assertOpened();
        ++$this->currentLine;

        return fputcsv($this->handler, $fields, $this->delimiter, $this->enclosure, $this->escape);
    }
Warning, this function will return exactly the same value as the fgetcsv() function.

@param array $fields

@throws \RuntimeException

@return int