Not working in Rails 4. NoMethodError for `fetch` and `with_indifferent_access`

[rex]

Gemfile

gem 'mongoid', '~> 4.0.0.beta1', github: 'mongoid/mongoid'
gem 'mongoid-indifferent-access', require: "mongoid_indifferent_access"

Model

class ServerdensityInstance
  include Mongoid::Document
  include Mongoid::Timestamps
  include Mongoid::Extensions::Hash::IndifferentAccess

  # Fields and methods and stuff
end

First Attempt

Controller Action

def show
  if ServerdensityInstance.where(serverdensity_id: params[:id]).exists?
    @imported = true
    @instance = ServerdensityInstance.find_by(serverdensity_id: params[:id])
  else
    @imported = false
    @instance = server_density.fetch_instance(params[:id])
  end
end

Which caused this error

NoMethodError at /servers/serverdensity/530074dcba6d13045777c0e6
undefined method `fetch' for #<ServerdensityInstance:0x007fb8dbcf5580>

The error placement in the view

- if @instance["providerId"].present?
  small = @instance["providerId"]
- elsif @instance["_id"].present? <<<<<<<<
  small= @instance["_id"]

But the @instance property is set as it should be.

@instance

#<ServerdensityInstance _id: 532cccfb5468653c69000000, ...<redacted>...

Second Attempt

I even tried to access it indirectly

instance = ServerdensityInstance.find_by(serverdensity_id: params[:id])
@instance = instance.with_indifferent_access

But that prompted this error:

NoMethodError at /servers/serverdensity/530074dcba6d13045777c0e6
undefined method `with_indifferent_access' for #<ServerdensityInstance:0x007fb8dbc2ed68>

Question

I am up a creek without a paddle here. I am sure there is something simple I am doing wrong. Can anyone provide me any insight?

Edit: Fixed

I spent a while churning through Mongoid's documentation and found the instance method attributes which resides on all documents and returns the document as HashWithIndifferentAccess. So,

This

ServerdensityInstance.find_by(serverdensity_id: params[:id])

Became this

ServerdensityInstance.find_by(serverdensity_id: params[:id]).attributes

But still, I would really rather use this awesome gem to eliminate the need for having to call attributes on every.single.document that I get back from MongoDB. :( I'm stuck.