Task/File/Csv/CsvWriterTask.php
protected function getInput(ProcessState $state)
    {
        $input = $state->getInput();
        if (!\is_array($input)) {
            throw new \UnexpectedValueException('Input value is not an array');
        }
        $splitCharacter = $this->getOption($state, 'split_character');

        /** @var array $input */
        foreach ($input as $key => &$item) {
            if (\is_array($item)) {
                $item = implode($splitCharacter, $item);
            }
        }

        return $input;
    }
protected function getInput(ProcessState $state)
    {
        $input = $state->getInput();
        if (!\is_array($input)) {
            throw new \UnexpectedValueException('Input value is not an array');
        }
        $splitCharacter = $this->getOption($state, 'split_character');

        /** @var array $input */
        foreach ($input as $key => &$item) {
            if (\is_array($item)) {
                $item = implode($splitCharacter, $item);
            }
        }

        return $input;
    }
@param ProcessState $state

@throws \UnexpectedValueException
@throws \InvalidArgumentException
@throws \Symfony\Component\OptionsResolver\Exception\ExceptionInterface

@return array