```ruby
module Feed2Email
  CONFIG_DIR = File.expand_path('~/.feed2email')

  def self.config
    @config ||= Config.new(File.join(CONFIG_DIR, 'config.yml'))
  end

  def self.logger
    @logger ||= Logger.new(config['log_path'], config['log_level'],
                           config['log_shift_age'], config['log_shift_size'])
  end

  def self.log(*args)
    logger.log(*args) # delegate
  end
end

require 'feed2email/config'
require 'feed2email/logger'
```

Use instance variables in module scope
user
```ruby
require 'feed2email/config'
require 'feed2email/logger'

module Feed2Email
  CONFIG_DIR = File.expand_path('~/.feed2email')

  def self.config; @config end

  def self.logger; @logger end

  def self.log(*args)
    logger.log(*args) # delegate
  end

  @config = Config.new(File.join(CONFIG_DIR, 'config.yml'))

  @logger = Logger.new(config['log_path'], config['log_level'],
                       config['log_shift_age'], config['log_shift_size'])
end
```
assistant