```ruby
class NamedJob < Struct.new(:perform)
  def display_name
    'named_job'
  end
end

class SimpleJob
  cattr_accessor :runs; self.runs = 0
  def perform; @@runs += 1; end
end

class ErrorJob
  cattr_accessor :runs; self.runs = 0
  def perform; raise 'did not work'; end
end             

class LongRunningJob
  def perform; sleep 250; end
end

class OnPermanentFailureJob < SimpleJob
  def failure
  end
end

module M
  class ModuleJob
    cattr_accessor :runs; self.runs = 0
    def perform; @@runs += 1; end    
  end
end

class CallbackJob
  cattr_accessor :messages

  def before(job)
    self.class.messages << 'before'
  end
  
  def perform
    self.class.messages << 'perform'
  end
  
  def after(job, error = nil)
    self.class.messages << 'after'
  end
  
  def success(job)
    self.class.messages << 'success'
  end

  def error(job, error)
    self.class.messages << "error: #{error.class}"
  end

  def failure(job)
    self.class.messages << 'failure'
  end
end
```

Remove arg from sample job
user
```ruby
class NamedJob < Struct.new(:perform)
  def display_name
    'named_job'
  end
end

class SimpleJob
  cattr_accessor :runs; self.runs = 0
  def perform; @@runs += 1; end
end

class ErrorJob
  cattr_accessor :runs; self.runs = 0
  def perform; raise 'did not work'; end
end             

class LongRunningJob
  def perform; sleep 250; end
end

class OnPermanentFailureJob < SimpleJob
  def failure
  end
end

module M
  class ModuleJob
    cattr_accessor :runs; self.runs = 0
    def perform; @@runs += 1; end    
  end
end

class CallbackJob
  cattr_accessor :messages

  def before(job)
    self.class.messages << 'before'
  end
  
  def perform
    self.class.messages << 'perform'
  end
  
  def after(job)
    self.class.messages << 'after'
  end
  
  def success(job)
    self.class.messages << 'success'
  end

  def error(job, error)
    self.class.messages << "error: #{error.class}"
  end

  def failure(job)
    self.class.messages << 'failure'
  end
end
```
assistant