Emits this instance as a Map according to the OAuth 2.0 specification.
Source
Map<String, dynamic> asMap() {
var map = {
"access_token": accessToken,
"token_type": type,
"expires_in":
expirationDate.difference(new DateTime.now().toUtc()).inSeconds,
};
if (refreshToken != null) {
map["refresh_token"] = refreshToken;
}
if (scopes != null) {
map["scope"] = scopes.map((s) => s.scopeString).join(" ");
}
return map;
}