how to accessed top level scope

module 
  def self.test
    "FOO"
  end
end
 
module Thing
  module 
    def self.test
      "BAR"
    end
  end
 
  def Thing.inner
    A.test
  end
 
  def Thing.outer
    ::A.test
  end
end
 
Thing.outer

Thing.inner
# => "BAR"