src/Neutrino/HttpClient/Request.php
public function setCookie($key, $value)
    {
        if (is_null($key)) {
            $this->cookies[] = $value;
        } else {
            $this->cookies[$key] = $value;
        }

        return $this;
    }
public function setCookie($key, $value)
    {
        if (is_null($key)) {
            $this->cookies[] = $value;
        } else {
            $this->cookies[$key] = $value;
        }

        return $this;
    }
Define a cookie

@param null|string $key
@param string $value

@return $this
@throws \InvalidArgumentException