Identity.custom constructor
Create custom identity.
provider
Your custom provider name.
userId
Unique user identifier for your custom provider.
token
Password of the user for your custom provider.
It's a string, provided by the developer and it will be
required by the GetSocial SDK to validate any future
intent to add this same identity to another user.
Implementation
Identity.custom(String provider, String userId, String token)
: this._(provider, userId, token);