186: test "Same user should not be able to submit multiple ratings for photo" do
    187:   user = FactoryGirl.create(:user)
    188:   photo = FactoryGirl.create(:photo)
    189:   user2 = FactoryGirl.create(:user2)
    190:   binding.pry
 => 191:   photo.rate(1,user)
    192:   photo.rate(3,user2) # Must have 2nd user to bypass error.
    193:   # Will return undefined method 'avg= ' without user2.
    194:   photo.rate(2,user)
    195:   assert_equal photo.rates.count, 2, "There are more than two ratings for the users"
    196: end

[1] pry(#<UserTest>)> photo.rate(1,user)
=> #<RatingCache:0x007fadf4849208
 id: 77,
 cacheable_id: 37,
 cacheable_type: "Photo",
 avg: 1.0,
 qty: 1,
 dimension: nil,
 created_at: Wed, 22 Jun 2016 19:07:19 UTC +00:00,
 updated_at: Wed, 22 Jun 2016 19:07:19 UTC +00:00>
[2] pry(#<UserTest>)> photo.rate(1,user)
NoMethodError: undefined method `avg=' for nil:NilClass
from /Users/rbennacer/.rvm/gems/ruby-2.3.0@mop2/gems/ratyrate-1.2.2.alpha/lib/ratyrate/model.rb:73:in `update_current_rate'
[3] pry(#<UserTest>)>