src/Services/BaseService.php
private function buildRequestHeaders($name, $request, $body)
    {
        $headers = [];

        if ($request->hasAttachment()) {
            $headers['Content-Type'] = 'multipart/related;boundary=MIME_boundary;type="application/xop+xml";start="<request.xml@devbay.net>";start-info="text/xml"';
        } else {
            $headers['Content-Type'] = 'text/xml';
        }

        if ($this->getConfig('compressResponse')) {
            $headers[self::HDR_RESPONSE_ENCODING] = 'application/gzip';
        }

        $headers['Content-Length'] = strlen($body);

        return array_merge($headers, $this->getEbayHeaders($name));
    }
private function buildRequestHeaders($name, $request, $body)
    {
        $headers = [];

        if ($request->hasAttachment()) {
            $headers['Content-Type'] = 'multipart/related;boundary=MIME_boundary;type="application/xop+xml";start="<request.xml@devbay.net>";start-info="text/xml"';
        } else {
            $headers['Content-Type'] = 'text/xml';
        }

        if ($this->getConfig('compressResponse')) {
            $headers[self::HDR_RESPONSE_ENCODING] = 'application/gzip';
        }

        $headers['Content-Length'] = strlen($body);

        return array_merge($headers, $this->getEbayHeaders($name));
    }
Helper function that builds the HTTP request headers.

@param string $name The name of the operation.
@param \DTS\eBaySDK\Types\BaseType $request Request object containing the request information.
@param string $body The request body.

@return array An associative array of HTTP headers.