src/Web/RequestHelper.php
public function getHeaders()
    {
        if ($this->_headers === null) {
            $this->_headers = new HeaderCollection();
            $headers = $this->reactRequest->getHeaders();
            foreach ($headers as $name => $value) {
                $this->_headers->add($name, $value);
            }
            $this->filterHeaders($this->_headers);
        }

        return $this->_headers;
    }
public function getHeaders()
    {
        if ($this->_headers === null) {
            $this->_headers = new HeaderCollection();
            $headers = $this->reactRequest->getHeaders();
            foreach ($headers as $name => $value) {
                $this->_headers->add($name, $value);
            }
            $this->filterHeaders($this->_headers);
        }

        return $this->_headers;
    }
Returns the header collection.
The header collection contains incoming HTTP headers.
@return HeaderCollection the header collection