We don't have to have the same method names of the Java SDK here. 

If possible, we should be using accessors for custom data the same way we do for other resources. For example, users should be able to do things like: 

```ruby
account.custom_data.custom_field = 'value'
account.save # this call should also save the custom field
account.custom_data.custom_field # this call should return 'value' from the server
```