const YahooFantasy = require('yahoo-fantasy');
const yf = new YahooFantasy(
  Y!APPLICATION_KEY,
  Y!APPLICATION_SECRET,
  tokenCallbackFn, // optional
  redirectUri // optional
);

yf.setUserToken(
  Y!OAuthAccessToken
);

// promise based
try {
  const meta = await yf.game.meta(game_key);
} catch (e) {
  // handle error
}

// callback based
yf.game.meta(game_key, callbackFn);

{
  "game_key": "328",
  "game_id": "328",
  "name": "Baseball",
  "code": "mlb",
  "type": "full",
  "url": "http://baseball.fantasysports.yahoo.com/b1",
  "season": "2014"
}