protected function getPrepareCorsHeaders($headers)
    {
        if (array_key_exists(CorsResponseHeaders::EXPOSE_HEADERS, $headers) === true) {
            $headers[CorsResponseHeaders::EXPOSE_HEADERS] =
                implode(', ', $headers[CorsResponseHeaders::EXPOSE_HEADERS]);
        }

        return $headers;
    }
protected function getPrepareCorsHeaders($headers)
    {
        if (array_key_exists(CorsResponseHeaders::EXPOSE_HEADERS, $headers) === true) {
            $headers[CorsResponseHeaders::EXPOSE_HEADERS] =
                implode(', ', $headers[CorsResponseHeaders::EXPOSE_HEADERS]);
        }

        return $headers;
    }
protected function getPrepareCorsHeaders ( $ headers ) { if ( array_key_exists ( CorsResponseHeaders :: EXPOSE_HEADERS , $ headers ) === true ) { $ headers [ CorsResponseHeaders :: EXPOSE_HEADERS ] = implode ( ', ' , $ headers [ CorsResponseHeaders :: EXPOSE_HEADERS ] ) ; } return $ headers ; }
There is an issue with IE which cannot work with multiple 'Access-Control-Expose-Headers' and
requires it them to be comma separated. Chrome and Firefox seem to be not affected.

@param array $headers

@return array

@see https://github.com/neomerx/cors-psr7/issues/31
There is an issue with IE which cannot work with multiple Access - Control - Expose - Headers and requires it them to be comma separated . Chrome and Firefox seem to be not affected .