signInUser static method
sign in an returns existing user with username
and password
Implementation
static Future<ParseUser> signInUser(String username, String password) async {
// ignore: omit_local_variable_types
final Map<String, String> tmpHead = {}
..addAll(_headers)
..['X-Parse-Revocable-Session'] = '1';
final content = Uri.encodeFull('username=$username&password=$password');
var response =
await http.get('$_url/parse/login?$content', headers: tmpHead);
_errorHandler(response);
return ParseUser._fromResponse(response);
}