createUser method 
    
      
Future<QBUser?>
createUser(
 - String login, 
- String password, {
- String? email, 
- int? blobId, 
- int? externalUserId, 
- int? facebookId, 
- String? fullName, 
- String? phone, 
- String? website, 
- String? customData, 
- List<String>? tags, 
}) 
    
    
  Implementation
  Future<QBUser?> createUser(String login, String password,
    {String? email,
    int? blobId,
    int? externalUserId,
    int? facebookId,
    int? twitterId,
    String? fullName,
    String? phone,
    String? website,
    String? customData,
    List<String>? tags}) async {
  Map<String, Object> data = Map();
  data["login"] = login;
  data["password"] = password;
  if (email != null) {
    data["email"] = email;
  }
  if (blobId != null) {
    data["blobId"] = blobId;
  }
  if (externalUserId != null) {
    data["externalUserId"] = externalUserId;
  }
  if (facebookId != null) {
    data["facebookId"] = facebookId;
  }
  if (twitterId != null) {
    data["twitterId"] = twitterId;
  }
  if (fullName != null) {
    data["fullName"] = fullName;
  }
  if (phone != null) {
    data["phone"] = phone;
  }
  if (website != null) {
    data["website"] = website;
  }
  if (customData != null) {
    data["customData"] = customData;
  }
  if (tags != null) {
    data["tags"] = tags;
  }
  Map<Object?, Object?> map = await _usersModule.invokeMethod(CREATE_METHOD, data);
  QBUser? qbUser = QBUserMapper.mapToQBUser(map);
  return qbUser;
}