# Imagine this is fpdf/fpdf_rotate.rb

module PDF_Rotate

  def initialize
    @angle = 0
  end

end


# Then in some other class:

class SomePDF

  require 'fpdf/fpdf_rotate'
  extend(PDF_Rotate)
end

foo = SomePDF.new
puts foo.angle


# angle will be undefined. How to define @angle in the module so that it inherits up to the class?