Amp\Artax\FormBody::getMultipartFieldArray PHP Method

    private function getMultipartFieldArray()
    {
        if (isset($this->cachedFields)) {
            return $this->cachedFields;
        }
        $fields = [];
        foreach ($this->fields as $fieldArr) {
            list($name, $field, $contentType, $fileName) = $fieldArr;
            $fields[] = "--{$this->boundary}\r\n";
            $fields[] = $field instanceof FileBody ? $this->generateMultipartFileHeader($name, $fileName, $contentType) : $this->generateMultipartFieldHeader($name, $contentType);
            $fields[] = $field;
            $fields[] = "\r\n";
        }
        $fields[] = "--{$this->boundary}--";
        return $this->cachedFields = $fields;
    }