我无法在watson-js演讲中将语言设置为西班牙文字api。我想我已尝试过以下各行的各种变体：
, xarg: "Content-Language=es-us"
有人有成就吗？怎么样？
exports.ATT_CREDS = {
client_id:"client_id"
, client_secret:"client_secret"
, access_token:"access_token"
, scope: "SPEECH"
, context: "Generic"
, access_token_url: "https://api.att.com/oauth/token"
, api_domain: "api.att.com"
, content_type: "audio/wav"
, xarg: "Content-Language=es-us"
};