int x = foo();  /* This is a comment  This is not code
  Continuation of comment */
int y = bar();

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// Create a callback which logs the current auth state
function authDataCallback(authData) {
  if (authData) {
    console.log("User " + authData.uid + " is logged in with " + authData.provider);
  } else {
    console.log("User is logged out");
  }
}
// Register the callback to be fired every time auth state changes
var ref = new Firebase("https://<YOUR-FIREBASE-APP>.firebaseio.com");
ref.onAuth(authDataCallback);