public static function env()
    {
        return function () {
            $appId = getenv(self::ENV_APP_ID);
            $certId = getenv(self::ENV_CERT_ID);
            $devId = getenv(self::ENV_DEV_ID);

            if ($appId && $certId && $devId) {
                return new Credentials($appId, $certId, $devId);
            } else {
                return new \InvalidArgumentException(
                    'Could not find environment variable '
                    . 'credentials in '. self::ENV_APP_ID . '/'
                    . self::ENV_CERT_ID . '/'
                    . self::ENV_DEV_ID
                );
            }
        };
    }
public static function env()
    {
        return function () {
            $appId = getenv(self::ENV_APP_ID);
            $certId = getenv(self::ENV_CERT_ID);
            $devId = getenv(self::ENV_DEV_ID);

            if ($appId && $certId && $devId) {
                return new Credentials($appId, $certId, $devId);
            } else {
                return new \InvalidArgumentException(
                    'Could not find environment variable '
                    . 'credentials in '. self::ENV_APP_ID . '/'
                    . self::ENV_CERT_ID . '/'
                    . self::ENV_DEV_ID
                );
            }
        };
    }
public static function env ( ) { return function ( ) { $ appId = getenv ( self :: ENV_APP_ID ) ; $ certId = getenv ( self :: ENV_CERT_ID ) ; $ devId = getenv ( self :: ENV_DEV_ID ) ; if ( $ appId && $ certId && $ devId ) { return new Credentials ( $ appId , $ certId , $ devId ) ; } else { return new \ InvalidArgumentException ( 'Could not find environment variable ' . 'credentials in ' . self :: ENV_APP_ID . '/' . self :: ENV_CERT_ID . '/' . self :: ENV_DEV_ID ) ; } } ; }
Provider that creates credentials from environment variables
EBAY_SDK_APP_ID, EBAY_SDK_CERT_ID, and EBAY_SDK_DEV_ID.

@return callable
Provider that creates credentials from environment variables EBAY_SDK_APP_ID EBAY_SDK_CERT_ID and EBAY_SDK_DEV_ID .