problem of $end solving approach?

end and $and

require 'ffi'
require 'capn_proto'
ADDRESSBOOK_SCHEMA = File.expand_path("../addressbook.capnp", __FILE__)
module AddressBook extend CapnProto::SchemaLoader
  load_schema(ADDRESSBOOK_SCHEMA)
end
  extend FFI::Library
  ffi_lib FFI::Library::LIBC
  attach_function :puts, [ :string ], :int
$end
Hello.puts("Hello, World")