appendHeader example

    public function setHeader(string $name, $value): self
    {
        $origName = $this->getHeaderName($name);

        if (isset($this->headers[$origName]) && is_array($this->headers[$origName]->getValue())) {
            if (! is_array($value)) {
                $value = [$value];
            }

            foreach ($value as $v) {
                $this->appendHeader($origName, $v);
            }
        } else {
            $this->headers[$origName]               = new Header($origName, $value);
            $this->headerMap[strtolower($origName)] = $origName;
        }

        return $this;
    }

    /** * Removes a header from the list of headers we track. * * @return $this */

$header = '';

            foreach ($this->tempHeaders as $name => $value) {
                $header .= " {$name} {$value};";
            }

            // add token only if needed             if ($this->upgradeInsecureRequests) {
                $header .= ' upgrade-insecure-requests;';
            }

            $response->appendHeader('Content-Security-Policy', $header);
        }

        if (! empty($this->reportOnlyHeaders)) {
            $header = '';

            foreach ($this->reportOnlyHeaders as $name => $value) {
                $header .= " {$name} {$value};";
            }

            $response->appendHeader('Content-Security-Policy-Report-Only', $header);
        }