try to run it and have got uninitialized constant ApplicationRecord (NameError)

[comcava]

ruby students_details_server.rb
DEPRECATION WARNING: PaperTrail.config.track_associations has not been set. As of PaperTrail 5, it defaults to false. Tracking associations is an experimental feature so we recommend setting PaperTrail.config.track_associations = false in your config/initializers/paper_trail.rb (called from require at /Users/dan/.rvm/rubies/ruby-2.4.3/lib/ruby/site_ruby/2.4.0/bundler/runtime.rb:81)
/Users/dan/work/grpc_with_ruby/app/models/student.rb:1:in <top (required)>': uninitialized constant ApplicationRecord (NameError) from /Users/dan/work/grpc_with_ruby/app/models.rb:9:in block in <top (required)>'
from /Users/dan/work/grpc_with_ruby/app/models.rb:8:in each' from /Users/dan/work/grpc_with_ruby/app/models.rb:8:in <top (required)>'
from /Users/dan/work/grpc_with_ruby/app.rb:2:in block in <top (required)>' from /Users/dan/work/grpc_with_ruby/app.rb:1:in each'
from /Users/dan/work/grpc_with_ruby/app.rb:1:in <top (required)>' from /Users/dan/work/grpc_with_ruby/lib/students_details_service.rb:10:in <top (required)>'
from students_details_server.rb:3:in require' from students_details_server.rb:3:in

'

[comcava]

But actuall I have in app/models

frozen_string_literal: true

class ApplicationRecord < ActiveRecord::Base
self.abstract_class = true

has_paper_trail
end