```ruby
require 'active_record'
require 'logger'

# Load all ruby files from 'cloud_cost_tracker' directory
Dir[File.join(File.dirname(__FILE__), "cloud_cost_tracker/**/*.rb")].each {|f| require f}

module CloudCostTracker

  # The default polling interval in seconds
  # This. can be overriden when a CloudCostTracker::Tracker is created, either
  # in the +accounts+ definitions, or in the +options+ parameter
  DEFAULT_POLLING_TIME = 300   # by default, poll all accounts every 5 minutes

  # Returns a slightly-modified version of the default Ruby Logger
  def self.default_logger
    logger = ::Logger.new(STDOUT)
    logger.sev_threshold = Logger::INFO
    logger.formatter = proc {|lvl, time, prog, msg|
      "#{lvl} #{time.strftime '%Y-%m-%d %H:%M:%S %Z'}: #{msg}\n"
    }
    logger
  end

  # Returns a Class object, which is some subclass of BillingClass
  # based on the +fog_provider+, +fog_service+, and +fog_collection+
  def self.get_billing_policy_class(fog_provider, fog_service, fog_collection)
    policy_class_name = "#{fog_collection.capitalize}BillingPolicy"
    provider_module = CloudCostTracker::Billing::const_get fog_provider
    service_module = provider_module.send(:const_get, fog_service)
    policy_exists = service_module.send(:const_defined?, policy_class_name)
    policy_exists ? service_module.send(:const_get, policy_class_name) : nil
  end
end
```

Remove unneeded CloudCostTracker static class method
user
```ruby
require 'active_record'
require 'logger'

# Load all ruby files from 'cloud_cost_tracker' directory
Dir[File.join(File.dirname(__FILE__), "cloud_cost_tracker/**/*.rb")].each {|f| require f}

module CloudCostTracker

  # The default polling interval in seconds
  # This. can be overriden when a CloudCostTracker::Tracker is created, either
  # in the +accounts+ definitions, or in the +options+ parameter
  DEFAULT_POLLING_TIME = 300   # by default, poll all accounts every 5 minutes

  # Returns a slightly-modified version of the default Ruby Logger
  def self.default_logger
    logger = ::Logger.new(STDOUT)
    logger.sev_threshold = Logger::INFO
    logger.formatter = proc {|lvl, time, prog, msg|
      "#{lvl} #{time.strftime '%Y-%m-%d %H:%M:%S %Z'}: #{msg}\n"
    }
    logger
  end

end
```
assistant