except method
Implementation
Map<String, dynamic> except(dynamic key) {
Map<String, dynamic> requestItems = _all;
if (key is List<String>) {
for (String vKey in key) {
requestItems.removeWhere((iKey, value) => iKey == vKey);
}
}
if (key is String) {
requestItems.removeWhere((vkey, value) => vkey == key);
}
return requestItems;
}