
| Name | Description | Type | Use | 
|---|---|---|---|
| credentials | A user credentials JSON object. | object | required | 
The credentials object can contain any properties. For example,
      it can be structured as follows.
{
  identifier,
  password
}Where identifier stands for a required user identifier property and
        password stands for a required user password property.
This method returns a promise object, which can be in one of the following states:
Resolve - confirms that the operation has completed successfully.
Reject - returns an object that is an instance of a generic Error
            class, as described below.
{
  "name": error_code
  "message": detailed_message
}
Where error_code stands for one of the error codes described in the
      Constants section of the Authentication article and
      detailed_message can be an additional message from the native
      side.