src/Router/Response.php
public function headers($headers = false)
    {
        $this->headers = array_unique(array_merge($this->headers, $headers));

        return $this;
    }
public function headers($headers = false)
    {
        $this->headers = array_unique(array_merge($this->headers, $headers));

        return $this;
    }
@param bool $headers

@return $this