initialize!

initialize.rb

# Initialize the application passing the given group. By default, the
# group is :default
def initialize!(group = :default) #:nodoc:
  raise "Application has been already initialized." if @initialized
  run_initializers(group, self)
  @initialized = true
  self
end
def run_initializers(group = :default, *args)
  return if instance_variable_defined?(:@ran)
  initializers.tsort_each do |initializer|
    initializer.run(*args) if initializer.belongs_to?(group)
  end
  @ran = true
end