How to successfully Throttle or use ignore_if option for exception_notification gem for Rails

How to successfully Throttle or use ignore_if option for exception_notification gem for Rails

### HOW TO IMPLEMENT EXCEPTION THROTTLING WITH EXCEPTION NOTIFIER FOR RAILS
###
### Documentation for Exception Notification: https://github.com/smartinez87/exception_notification

### SETUP VARIABLES
cache_key = "exception_times"

if ["development", "test"].include?(Rails.env.to_s)
  throttle_interval = 0 ### no throttling for dev
else
  throttle_interval = 5.minutes
end


### CALLBACK FOR ignore_if
throttle_error = ->(env, exception){ 
  exception_times = Rails.cache.read(cache_key)
  
  if exception_times.nil?
    Rails.cache.write({})
  end

  ### First Cleanup old exception times so hash doesnt get massive
  exception_times.reject!{|k,v| v <= (Time.now - throttle_interval) }

  ### Define Identifier for grouping the exceptions (customize as needed)
  identifier = [
    exception.name,
    env.ip,
    exception.backtrace.first,
  ].join("/")

  ### Throttle Logic
  last_time = exception_times[identifier]
    
  if last_time && Time.now <= (last_time + throttle_interval)
    exception_times[identifier] = Time.now

    throttle = false ### do not throttle the exception
  else 
    throttle =  true ### throttle the exception
  end

  ### Save to Cache
  Rails.cache.store("exception_times", exception_times)

  next throttle
}


### Exception Notification Setup
Rails.application.config.middleware.use(ExceptionNotification::Rack, {
  email: {
    email_prefix: "[EXCEPTION] ",
    sender_address: %{"Exception Notifier" <#{NOTIFICATIONS_EMAIL}>},
    exception_recipients: [DEV_EMAIL],
  },

  ignore_if: throttle_error,
})