Ruby Language Loading Source Files Automatically loading source files
Example
The method Kernel#autoload registers filename to be loaded (using Kernel::require) the first time that module (which may be a String or a symbol) is accessed.
autoload :MyModule, '/usr/local/lib/modules/my_module.rb'
The method Kernel#autoload? returns filename to be loaded if name is registered as autoload.
autoload? :MyModule #=> '/usr/local/lib/modules/my_module.rb'
