nl_tokens: Loads the credentials from the instance metadata service
pl_tokens: function refresh ( callback ) { var self = this ; if ( ! callback ) callback = function ( err ) { if ( err ) throw err ; } ; self . metadataService . loadCredentials ( function ( err , creds ) { if ( ! err ) { self . expired = false ; self . metadata = creds ; self . accessKeyId = creds . AccessKeyId ; self . secretAccessKey = creds . SecretAccessKey ; self . sessionToken = creds . Token ; self . expireTime = new <mask> ( creds . Expiration ) ; } callback ( err ) ; } ) ; }